JP2018187915A - Three-dimensional object printing system and three-dimensional object printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional object printing system and a three-dimensional object printing method, which dispense with control of rotation of a three-dimensional object and which enable high-definition printing to be performed without use of a fixture.SOLUTION: A three-dimensional object printing system includes: a printing table T for being loaded with a plurality of three-dimensional objects 10 serving as printing objects; detection means 101 for detecting the position and direction of each three-dimensional object loaded on the printing table; printing data generation means 102 for generating printing data corresponding to each three-dimensional object on the basis of the result of detection by the detection means; printing means 103 for performing printing on each three-dimensional object by the printing data generated by the printing data generation means; and control means 104 for controlling operations of the detection means, the printing data generation means and the printing means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional object printing system and a three-dimensional object printing method.

  Conventionally, as a three-dimensional object printing apparatus that prints an image on a three-dimensional object, an ink jet recording head and a three-dimensional object that rotatably supports the three-dimensional object in a state where the side surface of the three-dimensional object is opposed to the nozzle surface of the recording head. There is known a printer that includes a support unit and prints an image on a side surface of a three-dimensional object by a recording head while the three-dimensional object is rotated by the three-dimensional object support unit (see Patent Document 1).

JP 2006-335019 A

  However, the three-dimensional object printing apparatus according to the related art has a disadvantage that the production efficiency when printing on a plurality of three-dimensional objects is low because the three-dimensional object that can be rotated by the three-dimensional object support unit is single.

  In the prior art, in order to improve the print quality, it is necessary to appropriately control the rotation of the three-dimensional object as a print target. For this reason, complicated and precise control technology is required, and the cost is increased.

  Furthermore, a method using a printing jig has been proposed as a three-dimensional object printing method. However, such a printing method requires a printing jig for each three-dimensional object having a different shape, and requires a labor for fixing the three-dimensional object to the printing jig. Therefore, there is a problem that the cost required for printing increases.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a three-dimensional object printing system and a three-dimensional object printing method that do not require rotation control of a three-dimensional object and can perform high-definition printing without using a fixing jig. It is said.

  In order to solve the above problems, a three-dimensional object printing system according to the present invention detects a print table on which a plurality of three-dimensional objects as print targets are placed, and the position and orientation of each three-dimensional object placed on the print table. Detection means, print data generation means for generating print data corresponding to each solid object based on a detection result by the detection means, and each solid object by the print data generated by the print data generation means The gist of the invention includes a printing unit that executes printing on the printer, and a control unit that controls operations of the detection unit, the print data generation unit, and the printing unit.

  A three-dimensional object printing method according to another invention generates a print process corresponding to each three-dimensional object based on a detection process for detecting the position and orientation of each three-dimensional object placed on a print table and the detection result. The gist of the invention is to include a print data generation process and a print process for executing printing on each of the three-dimensional objects by the generated print data.

  According to the present invention, it is possible to provide a three-dimensional object printing system and a three-dimensional object printing method that do not require rotation control of a three-dimensional object and can perform high-definition printing without using a fixing jig.

It is a functional block diagram which shows the whole structure of the solid thing printing system which concerns on 1st Embodiment. It is explanatory drawing which shows the structural example of the solid thing printing system which concerns on 1st Embodiment. It is explanatory drawing which shows the production | generation procedure of print rendering data. It is explanatory drawing which shows the continuation of the production | generation procedure of print rendering data. It is explanatory drawing which shows the continuation of the production | generation procedure of print rendering data. It is explanatory drawing which shows the procedure which discovers a detection reference point by pattern matching. It is explanatory drawing (a)-(c) which shows the example of the production | generation procedure of print data. It is an imaging figure which shows the Example of a detection reference mark. It is explanatory drawing (a) and (b) which show the example of printing to a solid object. It is a partially enlarged view (a) and (b) showing an example of printing on a three-dimensional object. It is a schematic block diagram which shows the belt conveyor type printing table applied to the solid thing printing system which concerns on 1st Embodiment. It is a functional block diagram which shows the whole structure of the solid thing printing system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the principal part of the solid thing printing system which concerns on 2nd Embodiment. It is explanatory drawing which shows the structural example of the solid thing printing system which concerns on 2nd Embodiment. It is a schematic block diagram (a) and (b) which shows the structural example of the principal part of the solid thing printing system which concerns on 2nd Embodiment. It is explanatory drawing which shows the detection principle of a solid attitude | position. It is explanatory drawing which shows the example of the illumination angle and attitude | position angle in the detection of a three-dimensional attitude | position. It is explanatory drawing which shows the other example of the illumination angle and attitude | position angle in the detection of a three-dimensional attitude | position. It is a flowchart which shows the process sequence of the correction | amendment process performed with the solid object printing system which concerns on 2nd Embodiment. It is explanatory drawing which shows the production | generation procedure of the correction data in a correction process. It is explanatory drawing which shows the production | generation procedure of the correction data in a correction process. It is explanatory drawing which shows the production | generation procedure of the correction data in a correction process. It is explanatory drawing which shows the example of storage of a print data group. It is explanatory drawing which shows the relationship between the scanning direction of a scanning print head, the flying angle of an ink droplet, etc. FIG. It is explanatory drawing which shows the scanning direction and scanning example of a scanning print head.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members, and duplicate descriptions are omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

(First embodiment)
A configuration example of the three-dimensional object printing system S1 according to the first embodiment will be described with reference to FIGS.

  Here, FIG. 1 is a functional block diagram showing the overall configuration of the three-dimensional object printing system S1 according to the first embodiment, and FIG. 2 is an explanation showing an example of the configuration of the three-dimensional object printing system S1 according to the first embodiment. FIG.

  As illustrated in FIG. 1, the three-dimensional object printing system S <b> 1 includes a print table T on which a plurality of three-dimensional objects 10 to be printed are placed, and the positions of the three-dimensional objects 10, 10... Placed on the print table T. And a detection unit 101 that detects the orientation, a print data generation unit 102 that generates print data corresponding to each three-dimensional object 10 based on a detection result by the detection unit 101, and a print data generation unit 102 that generates the print data. Control for controlling the operation of the printing means 103 that executes printing on each three-dimensional object 10, the detection means 101, the print data generation means 102, and the printing means (for example, a flatbed UV inkjet printer) 103 according to the print data. Means 104.

  The detection unit 101 can be configured by a predetermined optical sensor or a three-dimensional sensor 200 that acquires three-dimensional posture information of each three-dimensional object 10 placed on the print table T.

  On the print table T, detection standards 15 that can be detected by the optical sensor (three-dimensional sensor) 200 are formed by printing at four corners.

  The detection unit 101 includes an instruction unit 105 configured by an XY slider 301 or the like that instructs a plurality of detection points on the surface of the three-dimensional object 10 in advance. In FIG. 2, the symbol B indicates a light beam, and the symbol 300 indicates a printer casing.

  The detection means 101 detects the position of the detection point indicated by the instruction means and the position of the detection reference for each three-dimensional object 10, and the control means 104 constituted by the workstations 104A, 104B, etc. Based on the position of the point and the position of the detection reference, the position and rotation angle of each three-dimensional object 10 on the print table T are calculated.

  In addition, the control unit 101 determines the posture of each solid object 10 by pattern matching based on the calculated data regarding the position and rotation angle of each solid object 10 and data regarding the posture of the solid object 10 acquired in advance. Can be.

  The print data generation unit 102 can be configured by a workstation 104B as hardware and predetermined data processing software.

  The print data generation unit 102 generates first print data (drawing data) based on the posture of each solid object 10 determined by the control unit 104 and the drawing information to be printed on the surface of each solid object 10. 102 A of the 1st production | generation means and the 2nd which produces | generates the 2nd printing data optimized by performing a rotation process to 1st printing data according to the position and rotation angle of each solid object 10 which were detected by the detection means 101 Generating means 102B.

  In addition, you may make it further provide the height detection means which detects height about each solid object 10 mounted in the printing table T. FIG.

  In this case, the print data generation unit can correct the second print data based on the height information of each three-dimensional object 10 detected by the height detection unit.

  When the optical sensor is configured with a three-dimensional sensor that acquires three-dimensional posture information of each three-dimensional object 10 placed on the print table T, the first generation unit 102A detects the three-dimensional sensor. Based on the result, the first print data is generated, and the second generation unit 102B generates the first print data according to the position and rotation angle of each three-dimensional object 10 acquired by the three-dimensional sensor or other detection unit. You may make it produce | generate the 2nd print data optimized by performing a rotation process.

  Further, the optical sensor 200 may detect the printing state on the surface of each three-dimensional object 10, and the control unit 104 may determine whether printing is good or not based on the detection result of the printing state.

(Regarding the processing of the first generation means)
Here, details of the processing of the first generation unit 102A will be described.

  First, 3D CAD data having three-dimensional shape information about the three-dimensional object 10 and design data having information related to coloring and drawing applied to the surface of the three-dimensional object 10 are input to the first generation unit 102A.

  The first generation unit 102A receives 3D CAD data including posture information on the print table T.

  Note that the most stable posture on the print table T can be instructed and determined from the 3D CAD data on the operation screen of the workstation 104B constituting the first generation unit 102A.

  Next, 3D CAD data corresponding to the three-dimensional object posture information on the print table T and the drawing information are synthesized, and two-dimensional rendering data is extracted under the condition of the parallel fluoroscopic image.

  Next, first print data (drawing data) is generated from the extracted two-dimensional rendering data and depth information corresponding to the rendering data.

  More specifically, since a printing apparatus generally prints two-dimensional data on a plane, the printing characteristics for the depth away from the plane are different from the printing characteristics on the plane. Depth printing characteristics different from the plane are stored in advance, and optimum drawing data is generated from the depth information corresponding to the rendering data with reference to the stored characteristics.

  For example, in the case of an inkjet printing apparatus, it depends on the printing characteristics for the depth depending on the flying characteristics of the ink droplets. Therefore, in order to compensate for the disturbance of the printing characteristics due to the deterioration of the ink droplet landing accuracy at a relatively far position, the contour data with the depth is extended to the optimum drawing data.

(Procedure for generating print rendering data)
With reference to FIGS. 3 to 5, a print rendering data generation procedure in the three-dimensional object printing system S <b> 1 according to the first embodiment will be described.

  In the present embodiment, a mascot doll D1 is exemplified as the three-dimensional object 10 to be printed.

  In the generation procedure shown in FIG. 3, the direction of the mascot dolls D1a to D1d is operated on the operation screen 400 of the workstation 104B constituting the first generation means 102A by using a pointing device such as a mouse. The posture of the doll D1 is determined.

  Next, in the generation procedure shown in FIG. 4, 3D CAD data and design data (cloth design data in the example shown in FIG. 4 and the like) W1 of the mascot doll D1 in the determined posture are synthesized on the operation screen 400.

  In the generation procedure shown in FIG. 5, two-dimensional rendering data is extracted under the condition of a parallel light fluoroscopic image, and drawing data W1a is generated from the two-dimensional rendering data and depth information corresponding to the rendering data.

(Specific examples of detection means)
Next, with reference to FIG. 2 etc., the Example of the reader as the detection means 101 is described.

  In the embodiment shown in FIG. 2, the reading device (detection means) 101 includes an XY slider 301 disposed on the upper surface side of a housing 300 that accommodates a flatbed UV inkjet printer 103 and the like, and the XY slider 301 causes XY The three-dimensional sensor 200 is a digital camera that can move in the direction.

  Here, the print data of the UV inkjet printer 103 needs to be generated at a position that matches the position on the print table T of the three-dimensional object 10.

  The drawing position accuracy is set to 200 μ as a target value based on a preliminary investigation result, and the position of the three-dimensional object 10 on the print table T of the UV inkjet printer 103 can be detected with an accuracy of 100 μ and a rotation angle of 1 degree.

  The three-dimensional sensor 200 is composed of a digital camera having 24.78 million pixels, and the XY slider 301 captures the detection area A1 to A8 (see FIG. 7 etc.) divided into eight on the print table T. Move.

  Then, by the processing of the reading software installed in the workstation 104B, the reference point (a specific example will be described later) of the three-dimensional object 10 is specified by the digital camera, and the position and rotation angle on the print table are calculated from the reading result. To do.

  It should be noted that the acceleration / deceleration control of the XY slider 301 is performed so that an error does not occur in the read image due to the influence of vibration at the time of photographing, and the movement time between the detection areas is set to achieve both detection time reduction and reading accuracy. It is desirable to be 1 to 4 seconds.

  In addition, when the digital camera having 24.78 million pixels is used as described above, the size of the printing table T is 30 cm × 42 cm.

  Under such conditions, from the relationship between the size of the print table T corresponding to the reading area and the reading resolution, the size of the detection areas A1 to A8 in one shooting is set to 15 cm × 10.5 cm.

  Then, an XY slider 301 for moving the digital camera in a plane parallel to the plane of the print table T is disposed at a height of about 80 cm from the print table T.

  Note that it is important in terms of printing accuracy to reduce an error caused by the height dimension of the three-dimensional object 10 arranged on the print table T not matching the position on the print table T due to the photographing viewing angle.

  Although the correction calculation can be performed on the height that can be grasped in advance, in principle, it is necessary to reduce the viewing angle in order to eliminate the influence of the dimensional error or the solid posture error of the solid object 10.

  That is, it is preferable to design so as to satisfy the viewing angle of 5.7 degrees or less so that the influence of the height error of 0.5 mm is within the range of the reading error of 0.05 mm.

(About reading reference marks and pattern matching based on printing standards)
The reference point of the position information on the print table T of the three-dimensional object 10 read by the digital camera needs to coincide with the print reference with high accuracy.

  Therefore, a printing sheet is fixed on the printing table T, and a reference mark (detection reference) 15 as illustrated in FIG. 8 is printed on the printing sheet.

  The positional relationship with the reference mark 15 is determined from the photographing information, print data is generated, and printing is performed.

  More specifically, for example, a PET film of the same size as the table is fixed on a printing table T of A3 (297 mm × 420 mm) size, and detection marks are printed for each of the areas A1 to A8 (see FIGS. 7 to 10). .

  In the example shown in FIG. 8, FIG. 10, etc., four circles are printed at equal distances on a cross line with the reference points of the areas A1 to A8 as intersections.

  The detecting means 101 detects these four circles by pattern matching, finds the center points of the four circles, connects the opposing center points with straight lines, and determines the intersection as a reference point.

  Thereby, the printing standard and the detection standard of the printing unit 103 can be matched with high accuracy.

  Further, in order to determine the position and rotation angle (rotation angle in the plane of the printing table T) of each three-dimensional object 10 with high accuracy and in a short time from the photographing information by the digital camera, 2 of the contour information of the three-dimensional object 10 is obtained. Pattern matching processing is performed by designating feature points at or above the location as reading reference points.

  That is, for example, as shown in FIG. 6A, the contour information of the three-dimensional object 10 is acquired in advance, and the feature points P1 and P2 of the two contours are designated as reading reference points.

  Next, reading reference points Q1 and Q2 are extracted from the read image information of the digital camera by pattern matching (see FIG. 6B).

  Then, after extracting the two reading reference points Q1 and Q2, the center-of-gravity position C and the rotation angle θ1 of the three-dimensional object are determined.

  As shown in FIGS. 6B and 7, the contour data is used to detect the position and orientation of the three-dimensional object 10 on the print table T (the rotation angle θ1 in the plane of the print table T). Instruct two or more reading reference points.

  In the example shown in FIG. 7A, two to three three-dimensional objects 10 are placed in areas A1 to A8 of the print table T in random directions.

  Here, taking the area A4 as an example, the position (x1, y1) and the rotation angle (θ1) of the three-dimensional objects 10a to 10c are determined based on the reading reference point by the method shown on the side of FIG. Determine (see FIG. 7B).

  Then, the first generation unit 102A that generates the first print data (drawing data) based on the information of the positions and the rotation angles θ1 of all the three-dimensional objects 10 arranged on the print table T acquired as described above. Forward to.

  Next, the second generation unit 102B generates second print data that is optimized by performing rotation processing on the first print data in accordance with the position (x1, y1) and the rotation angle (θ1) of each three-dimensional object 10. To do.

  Note that the second print data can be generated such that the positional relationship with the data reference point when the reading reference point is printed matches or is a prescribed value. As a result, the reading determination position and the printing position can be matched with high accuracy.

  In the example shown in FIG. 7A, each three-dimensional object is placed in each of the areas A1 to A8 of the print table T, but each process is performed even at a position across the areas A1 to A8. This is possible by combining areas.

  Furthermore, even when there are a plurality of three-dimensional objects or drawing data, high-precision printing can be similarly performed by applying the present invention.

(Print execution example)
First, as shown in FIG. 9A and FIG. 10A, a plurality of three-dimensional objects 10 are arranged on the print table T.

  At this time, as long as the arrangement of the three-dimensional objects 10 maintains a predetermined posture on the print table T, the rotation angle and position of the print table T in the plane are free. Further, there is no limitation as long as the quantity of the three-dimensional object 10 is within a range that can be arranged on the print table T.

  Then, the position and rotation angle of each three-dimensional object 10 are detected by the above-described method, and the printing unit 103 is driven by the print data generated based on the detection result to execute printing on each three-dimensional object 10. . As a result, a printed product 10A as shown in FIGS. 9B and 10B can be obtained.

  Further, in the three-dimensional object printing system S1 according to the first embodiment, as shown in FIG. 11, the print table T is placed on a belt (for example, infinite) on which the three-dimensional object 10 is placed and can be moved from the upstream side to the downstream side. A belt conveyor 700 provided with a track belt B) can be used.

  The belt B is moved in the D10 direction (right direction in the drawing) by a driving device (not shown).

  A plurality of detection references (reading reference marks) 15 that can be detected by the detection means 200 are printed on the surface of the belt B.

  Here, the detection means 200 is disposed upstream of the ink jet printing apparatus 130 as the printing means. In FIG. 11, reference numeral 10 </ b> A indicates a three-dimensional object that has been subjected to predetermined printing by the printing unit 130.

(Second Embodiment)
A configuration example of the three-dimensional object printing system S2 according to the second embodiment will be described with reference to FIGS.

  In addition, about the structure similar to the solid thing printing system S1 which concerns on 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  Here, FIG. 12 is a functional block diagram illustrating an overall configuration of the three-dimensional object printing system S2 according to the second embodiment, and FIG. 13 is a block diagram illustrating a configuration of a main part of the three-dimensional object printing system S2.

  As shown in FIG. 12, in the three-dimensional object printing system S2 according to the second embodiment, the print data generation unit 102 includes a third generation unit 102C in addition to the first generation unit 102A and the second generation unit 102B. The point that the printing unit 103 includes the scanning print head 130 is different from the three-dimensional object printing system S1 according to the first embodiment.

  The scanning print head 130 can perform high-speed printing on the entire surface of the print table by sequentially scanning and moving on the print table.

  Here, as shown in FIG. 24, when the scanning print head 130 is a printing unit that scans at high speed (for example, the scanning direction D20), the ejected ink droplets 300A fly obliquely.

  Note that the approximate (assumed value) of the flying angle of the ink particles is, for example, a protrusion speed: 5 m / sec, a head scanning speed: 0.5 m / sec, and antan 0.1 = 5.7 deg.

  In addition, the ink droplet 200A may have a curved flight trajectory like the ink droplet 300B due to the influence of an air flow accompanying scanning of the scanning print head 130.

  Thus, when the three-dimensional surface is a curved surface due to the influence of the ink flying angle, the landing position of the ink droplet 300B is different from that on the plane, which affects the linearity and dimensional accuracy.

  In the example shown in FIG. 25, when the scanning direction of the scanning print head 130 is D20, linear printing P20a to P20d is performed on the three-dimensional objects 10a to 10d whose directions are changed every 90 degrees.

  As a result, linearity is maintained in linear prints P20a and P20c whose scanning direction is substantially parallel to D20.

  On the other hand, it can be seen that linearity is lost in the linear prints P20b and P20d whose scanning direction is substantially orthogonal to D20.

  Therefore, in the three-dimensional object printing system S2 according to the second embodiment, the printing unit 103 is configured by a printing apparatus including the ink jet scanning print head 130, and the print data generation unit 102 is ejected from the scanning print head 130. Based on the flying angle of the ink particles (ink droplets) to be formed and the shape of the drawing surface of each three-dimensional object, the third generation means 102C for generating optimized print data is provided.

  The control unit 104 configured by a workstation or the like controls the printing apparatus (printing unit 103) based on the print data optimized by the third generation unit 102C.

  Thereby, the ink droplet discharged from the scanning print head 130 can be landed on a desired position, and the printing accuracy can be improved.

  As shown in the block diagram of FIG. 13, the third generation unit 102 </ b> C includes a storage unit (for example, a flash memory) 501 for drawing surface solid shape data and a print data optimization unit 502. The third generation unit 102C is realized by, for example, cooperation between hardware such as a CPU and a RAM and software that executes correction processing described later. Details of the correction process will be described later.

  Further, in the three-dimensional object printing system S2 according to the second embodiment, as shown in FIG. 11 described above, the print table T is placed on a belt that can move from the upstream side to the downstream side on which the three-dimensional object 10 is placed. For example, you may make it comprise with the belt conveyor 700 provided with an endless track-like belt) B.

  In the three-dimensional object printing system S <b> 2 according to the second embodiment, the three-dimensional sensor 200 as a detection unit includes a two-dimensional sensor 200 </ b> A configured with a digital camera or the like, and an illumination configured with an LED light or the like that illuminates the three-dimensional object 10. And means 250.

  In the configuration example shown in FIG. 14 and FIG. 15A, four LED lights as the illumination unit 250 are provided every 90 degrees by the arm member 251 around the two-dimensional sensor 200A.

  In addition, it is preferable that there are a plurality of LED lights as the illumination unit 250 from the viewpoint of applying a predetermined shadow in order to grasp the posture of the three-dimensional object. For example, five or more LED lights may be provided.

  Further, as shown in FIG. 15B, an illumination unit 260 in which a plurality of LEDs and the like are arranged in a ring shape may be attached around the two-dimensional sensor 200A by an arm member 251.

  Then, the two-dimensional sensor 200A detects the shadow of the drawing surface of the three-dimensional object 10 formed by the illumination unit 250 (260), and acquires the three-dimensional posture of the three-dimensional object 10.

  Here, FIG. 16 is an explanatory diagram illustrating the principle of detection of a three-dimensional posture, FIG. 17 is an explanatory diagram illustrating examples of illumination angles and posture angles in detecting a three-dimensional posture, and FIG. 18 is a diagram illustrating illumination angles in detecting a three-dimensional posture. It is explanatory drawing which shows the other example of a posture angle.

  As shown in FIG. 16, when the light position of the illumination means 250 is on the right side (LZ + direction) in the figure, the irradiation angle to the three-dimensional object 10 is −θ, and the light position of the illumination means 250 is the left side (LZ in the figure). The irradiation angle to the three-dimensional object (for example, the doll's face) 10 in the − direction is + θ.

  Then, the uneven shadow pattern (depending on the combination of the illumination angle and the attitude angle) of the three-dimensional object 10 at a predetermined illumination angle (for example, −45 degrees, 0 degrees, +45 degrees) is acquired as shown in FIG. Store in memory etc.

  Accordingly, for example, the unevenness shadow of the three-dimensional object 10 placed on the belt B of the belt conveyor 700 shown in FIG. 11 is obtained by the detecting means 200 and collated with the database pattern, whereby each three-dimensional object 10 is checked. A solid angle (solid posture) can be detected.

  In addition, although illustration is abbreviate | omitted, the pattern of the shadow change of the up-down direction and the horizontal direction (what is called XYZ direction) of the solid object 10 may be acquired, and it may make it database and store. Thereby, the solid angle (three-dimensional posture) of each three-dimensional object can be detected with higher accuracy.

  Further, as shown in FIGS. 18A and 18B, a solid object 10 is irradiated with a predetermined light and dark pattern 801, and the solid angle (three-dimensional posture) of each three-dimensional object 10 is changed by the change in the light-dark pattern of the three-dimensional object 10. May be detected.

(About optimization of print data)
Here, before explaining the details of the correction process, a mechanism of print data correction (optimization) in the three-dimensional object printing system S2 according to the second embodiment will be described.

  In the three-dimensional object printing system S <b> 2 according to the second embodiment, a printing apparatus including an inkjet print head 130 is used as the printing unit 103.

  Therefore, due to the movement of the print head 130 in the scanning direction and the influence of the airflow, the trajectory on which the ink particles ejected from the print head 130 fly differs from the trajectory directly below the vertical.

  Note that the approximate (assumed value) of the flying angle of the ink particles is, for example, a protrusion speed: 5 m / sec, a head scanning speed: 0.5 m / sec, and antan 0.1 = 5.7 deg.

  Further, in printing on the three-dimensional object 10, it is necessary to accurately land the ink particles on positions having different heights (that is, the surface of the three-dimensional object having unevenness).

  In other words, if printing data generated for a two-dimensional printing target (for example, printing paper) is projected onto a three-dimensional object as it is and printing is performed, the landing position of the ink particles deviates from the initial target position. Therefore, there arises a problem that a desired printing result cannot be obtained.

  Therefore, in order to obtain a desired print result for the three-dimensional object 10, optimized print data is generated by performing corrections that take into account the deviation of the landing positions of the ink particle trajectories and heights, and the like. There is a need.

  Therefore, the third generation unit 102C or the like performs a correction process for generating optimized print data based on the flying angle of the ink particles ejected from the print head 130 and the shape of the drawing surface of each three-dimensional object 10. .

(About correction processing)
Next, with reference to the flowchart of FIG. 19 and the explanatory diagrams of FIGS. 20 to 23, the processing procedure of the correction process executed in the three-dimensional object printing system S2 according to the second embodiment will be described.

  When the correction process is started, first, the plane rotation angle of the three-dimensional object 10 is acquired by the detection unit 101, and the process proceeds to step S11.

  In step S11, original design data paired with three-dimensional data in pixel units is read from the storage device of the control means 104 or the like.

  Here, the original design data corresponds to basic print data obtained by the planar projection method in the standard posture of the three-dimensional object 10. In the coordinates illustrated in FIG. 20, a hatched pixel (area) PD1 corresponds to the basic print data.

  The basic print data includes height information H and curved surface information including adjacent pixels (pixel (x7, y9 in the example shown in FIG. 20)) for each pixel (pixel (x7, y9 in the example shown in FIG. 20)). ), And is stored in the storage device of the control means 104 or the like.

  In step S12, the three-dimensional posture of the three-dimensional object 10 is detected from the displacement angle of the standard posture, and the process proceeds to step S13.

  In step S13, the ink landing position based on the ink flying angle is predicted for each pixel.

  The example shown in FIGS. 21A and 21B is an example of predicting the ink landing position when the displacement of the three-dimensional object 10 is detected as the plane rotation angle 180 degrees and the displacement angle of the solid posture (5 degrees on the x-axis). It is.

  As shown in this prediction example, it can be seen that when the plane rotation angle is 180 ° and the three-dimensional posture is 5 °, the flying distance of the ink becomes longer and the landing position extends farther than the reference position.

  In the example shown in FIGS. 21A and 21B, the shape of the printing surface of the three-dimensional object 10 is a convex shape as shown, and the height (distance from the ink ejection surface 400) is as shown. Due to the difference, a difference occurs in the ink flight trajectories 300C and 300D and the landing positions.

  Such ink landing position prediction is executed for each pixel to generate ink landing position prediction data.

  Next, in step S14, a deviation between the ink landing position prediction data of the ink landing position and the target landing position is calculated for each pixel.

  In the example shown in FIG. 22, with respect to the original design data PD1 shown in FIG. 22A, the ink landing position is predicted to shift in the direction D11 as shown in FIG. 22B.

  Next, in step S15, corrected print data (for example, corrected print data PD2 shown in FIG. 22C) in which the ink landing position is corrected so as to be the target landing position is generated, and the process ends.

  It should be noted that the calculation result may be stored in advance in a flash memory or the like in order to perform a high-speed processing time for prediction of deviation of the ink landing position and calculation of correcting the ink landing position.

  That is, for example, as shown in FIG. 23, a non-volatile memory such as a flash memory or a hard disk device in a table format or the like as a print data group (corrected print data) obtained by associating a plane rotation angle with print data for each solid attitude angle Etc. can be stored.

  Further, in order to obtain a sufficient calculation accuracy on a practical scale for the amount of stored calculation results, a complementary process may be added to a plurality of stored calculation results.

  By executing printing on each three-dimensional object 10 using the corrected print data generated in this way, a plurality of three-dimensional objects 10 placed in a random direction and tilt are sequentially conveyed by the belt conveyor 700. On the other hand, desired printing can be accurately performed.

  Here, the optimum print data corresponding to the relationship between the ink flying angle and the drawing surface shape of the three-dimensional object 10 is generated and stored in a storage device or the like by generating an optimum print data group corresponding to each posture prepared in advance. It may be.

  In addition, when the optimum print data group corresponding to each prepared posture is missing data corresponding to the detected three-dimensional posture and the plane rotation angle, blank print data (for example, three-dimensional print data only) You may make it be in a state where nothing is printed on the object).

  Further, the calculation and storage of the missing data may be performed in parallel according to the history of the job in which the missing data has occurred. In this case, the optimum print data group can be grown by self-learning to improve productivity.

  As described above, according to the three-dimensional object printing system and the three-dimensional object printing method according to the present embodiment, it is possible to eliminate the need for trial and error until a printed material is obtained as in the past, and to increase production efficiency. it can.

  In addition, high-precision and high-definition printing can be performed on a plurality of three-dimensional objects without using a printing jig, and the printing cost can be reduced.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the embodiments disclosed herein are illustrative in all respects and are not limited to the disclosed technology. Should not be considered. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above embodiment, but should be construed according to the description of the scope of claims. All modifications that fall within the scope of the claims and the equivalent technology are included.

  For example, the printing unit 103 is not limited to a UV inkjet printer, and printers of various printing methods can be applied.

  Further, the control means 104 is not limited to a workstation, and a personal computer or the like may be used.

  Further, when the three-dimensional sensor is composed of illumination means and a two-dimensional camera, the determination of the three-dimensional posture of the three-dimensional object 10 corresponds to the shadow data of the drawing surface and the three-dimensional posture of the three-dimensional object stored in advance. You may make it perform by the comparison calculation with shadow data.

  In addition, a plurality of illumination means (LED lights 250, 260, etc.) having different irradiation angles with respect to the three-dimensional object are provided, and the three-dimensional object is obtained from a plurality of photographing results obtained by sequentially repeating the illumination process and the two-dimensional camera. The three-dimensional posture may be detected.

S1, S2 ... Solid object printing system 10 ... Solid object 15 ... Reference mark (detection standard)
DESCRIPTION OF SYMBOLS 101 ... Detection means 102 ... Print data generation means 102A ... First generation means 102B ... Second generation means 102C ... Third generation means 103 ... Printing means 104 ... Control means 105 ... Instruction means 130 ... Scanning print head 200 ... Optical sensor ( 3D sensor)
700 ... belt conveyor T ... printing table

Claims (14)

A printing table on which a plurality of three-dimensional objects as print targets are placed;
Detecting means for detecting the position and orientation of each three-dimensional object placed on the printing table;
Print data generation means for generating print data corresponding to each of the three-dimensional objects based on the detection result by the detection means;
Printing means for executing printing on each three-dimensional object using the print data generated by the print data generation means;
Control means for controlling operations of the detection means, the print data generation means and the printing means;
A three-dimensional object printing system comprising:   The three-dimensional object printing system according to claim 1, wherein the detection unit includes an optical sensor.   The three-dimensional object printing system according to claim 2, wherein a detection reference that can be detected by the optical sensor is formed on the printing table. The detection means includes instruction means for instructing a plurality of detection points in advance on the surface of the three-dimensional object,
The detection means detects the position of the detection point and the position of the detection reference indicated by the instruction means for each solid object,
The said control means calculates the position and rotation angle of each said solid object on the said print table based on the position of the said detected point detected, and the position of the said detection reference | standard. Three-dimensional printing system.   The control means determines the posture of each solid object by pattern matching based on the calculated data on the position and rotation angle of each solid object and data on the posture of the solid object acquired in advance. The three-dimensional object printing system according to claim 4. The print data generation means includes
First generation means for generating first print data based on the posture of each solid object determined by the control means and the drawing information to be printed on the surface of each solid object;
Second generation means for generating second print data that has been optimized by subjecting the first print data to rotation processing according to the position and rotation angle of each three-dimensional object detected by the detection means;
The three-dimensional object printing system according to claim 5, further comprising: Further comprising a height detecting means for detecting the height of each three-dimensional object placed on the printing table;
The three-dimensional object according to claim 6, wherein the print data generation unit corrects the second print data based on height information of the three-dimensional object detected by the height detection unit. Printing system. The optical sensor is a three-dimensional sensor that acquires three-dimensional posture information of each three-dimensional object placed on a printing table,
The first generation unit generates the first print data based on a detection result by the three-dimensional sensor,
The second generation unit performs a rotation process on the first print data in accordance with the position and rotation angle of each three-dimensional object acquired by the three-dimensional sensor or other detection unit, and optimizes the second print data. The three-dimensional object printing system according to claim 6, wherein print data is generated. The optical sensor detects a printing state on the surface of each three-dimensional object,
The three-dimensional object printing system according to any one of claims 2 to 8, wherein the control unit determines whether or not the printing is good based on a detection result of the printing state.   The said printing table is comprised by the belt conveyor provided with the belt which mounts the said solid object and can move to the downstream from an upstream side, It is any one of Claims 1-9 characterized by the above-mentioned. Three-dimensional printing system.   The three-dimensional object printing system according to claim 10, wherein the detection unit is disposed upstream of the printing unit. The printing means includes a printing apparatus including an ink jet print head,
The print data generation means includes
Further comprising third generation means for generating optimized print data based on the flying angle of the ink particles ejected from the print head and the shape of the drawing surface of each three-dimensional object;
12. The three-dimensional object printing system according to claim 1, wherein the control unit controls the printing apparatus based on print data optimized by the third generation unit. 13. The three-dimensional sensor includes a two-dimensional sensor and illumination means for illuminating the three-dimensional object.
The said two-dimensional sensor acquires the three-dimensional attitude | position of this solid object by detecting the shadow of the drawing surface of the said solid object formed by the said illumination means. The three-dimensional object printing system according to item 1. A detection process for detecting the position and orientation of each three-dimensional object placed on the printing table;
A print data generation process for generating print data corresponding to each three-dimensional object based on a detection result;
A printing process for executing printing on each of the three-dimensional objects according to the generated print data;
A three-dimensional object printing method characterized by comprising: