JP2018154015A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device which can inhibit distortion of an image formed on a recording medium having a three-dimensional shape.SOLUTION: An image formation device 1 includes an image formation part 4. The image formation part 4 forms an image on a recording medium S having a three-dimensional shape. The image formation part 4 has: at least one recording head 42; and a head holder 41. The recording head 42 forms the image on the recording medium S with ink. The head holder 41 holds the recording head 42. The recording head 42 has multiple nozzles 43. At least one nozzle 43 of the multiple nozzles 43 discharges the ink in a direction that is not parallel to a direction in which other nozzles 43 discharge the ink.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus.

  The image forming apparatus described in Patent Document 1 includes an image forming unit. The image forming unit forms an image on paper using ink. Specifically, the image forming unit includes a transport drum, a plurality of ink jet recording heads, and a head holder. The conveyance drum holds the sheet in a cylindrical shape. The transport drum rotates at a constant rotational speed. Each of the plurality of inkjet recording heads forms an image on a sheet using inks of different colors. The head holder holds each inkjet recording head side by side in the circumferential surface direction of the transport drum.

  Each inkjet recording head has a plurality of nozzles that eject ink. The plurality of nozzles are arranged in parallel along the axial direction of the transport drum. In addition, each of the plurality of nozzles is arranged such that the distance to the surface of the transport drum is a preset distance. In the image forming apparatus described in Patent Document 1, ink is ejected from each nozzle at a constant timing, and an image is formed on a sheet held on the surface of the transport drum.

JP 2009-274285 A

  However, in the image forming apparatus described in Patent Document 1, when the surface of a three-dimensional recording medium (paper held in a cylindrical shape) has a bulging portion, an image formed on the recording medium may be distorted. . The bulging portion swells from the peripheral surface of the transport drum. Specifically, when the surface of the recording medium has a bulging portion, the surface area of the recording medium increases at the bulging portion, so that the density of the ink adhering to the surface of the bulging portion is reduced and formed on the recording medium. The image may be distorted.

  An object of the present invention is to provide an image forming apparatus capable of suppressing distortion of an image formed on a three-dimensional recording medium.

  The image forming apparatus of the present invention includes an image forming unit. The image forming unit forms an image on a three-dimensional recording medium. The image forming unit includes at least one recording head and a head holder. The recording head forms an image with ink on the recording medium. The head holder holds the recording head. The recording head has a plurality of nozzles. At least one of the plurality of nozzles ejects ink in a direction non-parallel to the direction in which the other nozzle ejects ink.

  According to the present invention, distortion of an image formed on a three-dimensional recording medium can be suppressed.

1 is a side view showing an image forming apparatus according to Embodiment 1 of the present invention. 1 is a plan view showing an image forming apparatus according to Embodiment 1 of the present invention. It is a figure which shows the position information generation part and image formation part which concern on Embodiment 1 of this invention. 1 is a block diagram illustrating a configuration of an image forming apparatus according to Embodiment 1 of the present invention. It is a flowchart which shows the image formation process by the control part which concerns on Embodiment 1 of this invention. It is a side view which shows the image forming apparatus which concerns on Embodiment 2 of this invention. It is a top view which shows the image forming apparatus which concerns on Embodiment 2 of this invention. It is a side view which shows the image forming apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the image formation part which concerns on other embodiment of this invention.

  Hereinafter, an embodiment of an image forming apparatus 1 according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated. In addition, the drawings schematically show each component as a main component for easy understanding.

[Embodiment 1]
With reference to FIGS. 1 and 2, an image forming apparatus 1 according to Embodiment 1 of the present invention will be described. FIG. 1 is a side view showing a configuration of an image forming apparatus 1 according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing the configuration of the image forming apparatus 1 according to the first embodiment of the present invention. In FIG. 1, a vertical direction X and one horizontal direction Y orthogonal to the vertical direction X are defined.

  As shown in FIGS. 1 and 2, the image forming apparatus 1 forms an image on the surface of the recording medium S. The image forming apparatus 1 includes a base unit 11, a mounting table 12, a holder support unit 2, a position information generation unit 3, an image forming unit 4, a control unit 5, and an operation unit 6.

  In the present embodiment, the recording medium S is formed in a three-dimensional shape. Specifically, the recording medium S has a surface shape including at least one curved surface. The curved surface is formed in a protruding shape or a concave shape, for example. Specifically, the recording medium S is, for example, various parts, various models, various containers, or paper held in a three-dimensional shape.

  The mounting table 12 is formed in a disk shape, for example. The mounting table 12 has an upper surface portion and a first axis 13. The upper surface portion extends along the horizontal direction Y. A recording medium S is placed on the upper surface portion. The first axis 13 extends along the vertical direction X. The first axis 13 passes through the center of the upper surface portion.

  The base part 11 is placed on a flat part such as a floor surface, for example. The base part 11 is formed in a box shape. The base part 11 accommodates the control part 5 inside. An operation unit 6 is disposed on the surface portion of the base unit 11. A mounting table 12 is disposed on the upper surface of the base unit 11.

  The operation unit 6 includes, for example, a display unit and an input unit. The input unit includes a hard key. The input unit outputs an input signal corresponding to a user operation to the control unit 5. The user's operation includes, for example, operations for performing various settings of the image forming apparatus 1. The display unit includes a display. The display displays various screens. The display unit also functions as an input unit when it has a touch panel function.

  The holder support unit 2 supports the position information generation unit 3 and the image forming unit 4. The holder support part 2 is an example of a first support part and a second support part of the present invention. In the present embodiment, the first support portion and the second support portion are integrally formed. The holder support unit 2 includes a rotating unit 21, a first rotating shaft 22, a second rotating shaft 23, an elevating unit 24, and a second axis 14.

  The rotating unit 21 is an example of a first rotating unit and a second rotating unit of the present invention. In the present embodiment, the first rotating part and the second rotating part are integrally formed. The rotating unit 21 rotates around the first axis 13 on the outside of the recording medium S placed on the placing table 12. The rotating unit 21 is rotated by, for example, a predetermined driving unit accommodated in the base unit 11. The predetermined drive unit includes, for example, a rotation mechanism that rotates the rotation unit 21 around the first axis 13 and a power source that supplies power to the rotation mechanism. The rotating part 21 is formed in an annular shape, for example. The rotating unit 21 is supported by the base unit 11 so as to be positioned outside the mounting table 12.

  The elevating unit 24 is an example of a first elevating unit and a second elevating unit of the present invention. In the present embodiment, the first elevating part and the second elevating part are integrally formed. The elevating part 24 is disposed inside the base part 11. The elevating part 24 raises and lowers the rotating part 21 along the first axis 13. The elevating unit 24 includes, for example, a supporting member that supports the rotating unit 21, a moving mechanism that moves the supporting member in the vertical direction, and a drive source that supplies power to the moving mechanism.

  The first rotating shaft 22 is supported by the rotating unit 21. The first rotating shaft 22 rotates around the second axis 14. The second axis 14 extends along the horizontal direction Y. The second axis 14 is orthogonal to the first axis 13. In the present embodiment, the first rotating shaft 22 is disposed on both sides of the rotating unit 21. The first rotating shaft 22 extends toward the outside of the rotating unit 21. The first rotating shaft 22 is formed in a cylindrical shape.

  The first rotating shaft 22 turns around the first axis 13 as the rotating unit 21 rotates. The first rotating shaft 22 moves up and down along the first axis 13 as the rotating unit 21 moves up and down. Moreover, the 1st rotating shaft 22 is rotated by the predetermined drive part accommodated in the inside of the base part 11, for example. The predetermined drive unit includes, for example, a rotation mechanism that rotates the first rotation shaft 22 around the second axis 14 and a power source that supplies power to the rotation mechanism.

  The second rotating shaft 23 is supported by the rotating unit 21. Specifically, a part of the second rotating shaft 23 is inserted into the first rotating shaft 22, and one end of the second rotating shaft 23 is supported by the rotating unit 21. The second rotating shaft 23 rotates around the second axis 14. The second axis 14 is an example of the third axis of the present invention. In the present embodiment, the second rotating shaft 23 is disposed on both sides of the rotating unit 21. The second rotating shaft 23 extends toward the outside of the rotating unit 21. The second rotating shaft 23 is formed in a columnar shape, for example.

  The second rotating shaft 23 turns around the first axis 13 as the rotating unit 21 rotates. The second rotating shaft 23 moves up and down along the first axis 13 as the rotating unit 21 moves up and down. Moreover, the 2nd rotating shaft 23 is rotated by the predetermined drive part accommodated in the inside of the base part 11, for example. The predetermined drive unit includes, for example, a rotation mechanism that rotates the second rotation shaft 23 around the second axis 14 and a power source that supplies power to the rotation mechanism.

  The image forming unit 4 forms an image on the recording medium S mounted on the mounting table 12. The image forming unit 4 has a head holder 41. In the present embodiment, the head holder 41 is formed in an arc shape. The head holder 41 is disposed across one first rotating shaft 22 and the other first rotating shaft 22 opposite to the one. The head holder 41 rotates around the second axis 14 on the outside of the recording medium S placed on the placing table 12 as the first rotating shaft 22 rotates. The head holder 41 rotates about the first axis 13 as the rotating unit 21 rotates. The head holder 41 moves up and down along the first axis 13 as the rotating unit 21 moves up and down.

  The position information generation unit 3 generates position information. The position information indicates the position of the surface of the recording medium S mounted on the mounting table 12. The position information generation unit 3 outputs the position information to the control unit 5.

  The position information generation unit 3 has a camera holder 31. The camera holder 31 is an example of the detection unit holder of the present invention. In the present embodiment, the camera holder 31 is formed in an arc shape. The camera holder 31 is disposed across one second rotating shaft 23 and the other second rotating shaft 23 opposite to the one. The camera holder 31 is disposed outside the head holder 41. The camera holder 31 turns around the second axis 14 along with the rotation of the second rotation shaft 23. The camera holder 31 rotates about the first axis 13 as the rotating unit 21 rotates. The camera holder 31 moves up and down along the first axis 13 as the rotating unit 21 moves up and down.

  The control unit 5 includes, for example, a processor and a storage unit. The processor is, for example, a CPU (Central Processing Unit). The storage unit includes, for example, a semiconductor memory and an HDD (Hard Disk Drive). The processor controls the position information generating unit 3 and the image forming unit 4 based on the computer program stored in the storage unit.

  Next, the configuration of the position information generation unit 3 and the image forming unit 4 will be further described with reference to FIG. FIG. 3 is a diagram illustrating the configuration of the position information generation unit 3 and the image forming unit 4. Specifically, FIG. 3 shows a part of the position information generation unit 3 and a part of the image forming unit 4.

  As shown in FIG. 3, the position information generation unit 3 further includes a plurality of image sensors 32 in addition to the camera holder 31. The camera holder 31 holds a plurality of image sensors 32. The camera holder 31 holds a plurality of imaging elements 32 so as to be aligned in the circumferential direction of the virtual circumferential surface with the first axis 13 as the center. The camera holder 31 holds a plurality of imaging elements 32 at intervals in the circumferential direction.

  The plurality of image sensors 32 are an example of a plurality of detection units of the present invention. The plurality of imaging elements 32 detect reflected light from the recording medium S. In the present embodiment, the image sensor 32 images the recording medium S. Each of the plurality of imaging elements 32 receives reflected light from a direction that is not parallel to the direction in which the other imaging elements 32 detect reflected light. In the present embodiment, the plurality of image pickup devices 32 are held by the camera holder 31 so as to face one point on the first axis 13. Each imaging device 32 images the recording medium S placed on the mounting table 12 described with reference to FIGS. 1 and 2. Thereby, each imaging device 32 generates imaging information indicating the recording medium S as position information. Each image sensor 32 outputs position information to the control unit 5 described with reference to FIG.

  The image forming unit 4 further includes a plurality of recording heads 42 in addition to the head holder 41. The plurality of recording heads 42 are held by a head holder 41. The plurality of recording heads 42 form images on the recording medium S with different color inks. In the present embodiment, the plurality of recording heads 42 includes a recording head 42y corresponding to yellow, a recording head 42m corresponding to magenta, a recording head 42c corresponding to cyan, and a recording head 42k corresponding to black. Including. In the present embodiment, the plurality of recording heads 42 are arranged side by side in the thickness direction of the head holder 41. Each of the plurality of recording heads 42 has a plurality of nozzles 43.

  The recording head 42y is connected to an ink tank (not shown) that contains yellow ink. The recording head 42m is connected to an ink tank (not shown) containing magenta ink. The recording head 42c is connected to an ink tank (not shown) that contains cyan ink. The recording head 42k is connected to an ink tank (not shown) that contains black ink. Each ink tank is accommodated in the base part 11 demonstrated with reference to FIG.1 and FIG.2, for example.

  The recording head 42y has a plurality of nozzles 43y. Each of the plurality of nozzles 43y ejects ink in a direction non-parallel to the direction in which the other nozzles 43y eject ink. The plurality of nozzles 43 y are arranged so as to eject ink toward a point on the first axis 13.

  The recording head 42y ejects ink by a piezo method. Specifically, the recording head 42y has a liquid chamber, a diaphragm, and a piezoelectric element for each nozzle 43y. A pulse having a predetermined waveform is input to the piezoelectric element when ink is ejected. The piezo element is deformed to correspond to the pulse. As a result, the pressure due to the deformation of the piezoelectric element is transmitted to the diaphragm, and the diaphragm is deformed. Then, ink is ejected from the nozzles 43y due to the change in volume of the liquid chamber accompanying the deformation of the diaphragm. The recording heads 42m, 42c, and 42k are configured in the same manner as the recording head 42y, and thus description thereof is omitted here.

  Next, the control unit 5 will be further described with reference to FIGS. FIG. 4 is a block diagram illustrating a configuration of the image forming apparatus 1. As illustrated in FIG. 4, the image forming apparatus 1 according to the present embodiment is connected to, for example, an external input device 7 disposed outside the image forming apparatus 1.

  The external input device 7 can input image data to the control unit 5. The external input device 7 is a personal computer, for example. The image data indicates an image corresponding to the surface shape of the recording medium S. That is, the image data indicates a three-dimensional image. Specifically, the image data indicates a plurality of pixels that divide the surface of the recording medium S and a color set for each pixel.

  For example, the control unit 5 controls the position information generation unit 3 to generate position information on the surface of the recording medium S based on an operation signal input from the operation unit 6. Specifically, the control unit 5 operates the camera holder 31 and causes the plurality of imaging elements 32 to image the recording medium S. Here, the operation of the camera holder 31 is performed by rotating around the first axis 13 described with reference to FIGS. 1 and 2, moving up and down along the first axis 13, and turning around the second axis 14. including. As a result, position information is input to the control unit 5 from the position information generation unit 3.

  The control unit 5 acquires position data based on the position information. The position data indicates the position of the surface of the recording medium S mounted on the mounting table 12. In other words, the position data indicates the three-dimensional shape (surface shape) of the recording medium S placed on the placing table 12.

  Further, the control unit 5 determines the operation pattern of the recording head 42 based on the image data and the position data. The operation pattern of the recording head 42 includes the rotation about the first axis 13 described with reference to FIGS. 1 and 2, the elevation along the first axis 13, and the rotation about the second axis 14. .

  When determining the operation pattern of the recording head 42, the control unit 5 determines the position of the surface of the recording medium S indicated by the position data and the surface shape of the recording medium S indicated by the image data based on the image data and the position data. Rotate the image data so that they match. Specifically, the control unit 5 associates each position on the surface of the recording medium S indicated by the position data with each pixel position in the three-dimensional shape indicated by the image data. In other words, the control unit 5 specifies the position of each pixel indicated by the image data in the three-dimensional shape of the recording medium S indicated by the position data. Hereinafter, the specified position of each pixel is referred to as an ink landing position.

  The control unit 5 selects a nozzle 43 that ejects ink for each ink landing position. The nozzles 43 that eject ink are nozzles 43 that can move to positions where ink can be ejected toward the corresponding ink landing positions.

  In the image forming apparatus 1 of the present embodiment, the ink ejected from the plurality of nozzles 43 is ejected toward one point on the first axis 13. For this reason, when the distance between the nozzle 43 that ejects the ink and the surface of the recording medium S is longer than the first threshold, the ink may be excessively supplied to the surface of the recording medium S. The first threshold is set based on the radius of curvature R of the virtual circumferential surface where the plurality of nozzles 43 are arranged in the circumferential direction, the arrangement pitch of the plurality of nozzles 43, and the pixel pitch of the pixels indicated by the image data. Specifically, the first threshold value is represented by an expression of (n−1) R / n when the nozzles 43 are arranged at an arrangement pitch n times the pixel pitch of the pixel indicated by the image data, for example. .

  In the present embodiment, the control unit 5 calculates the distance L between the nozzle 43 that ejects ink and the surface of the recording medium S before selecting the nozzle 43 that ejects ink. When the distance L is larger than the first threshold and smaller than the second threshold, the control unit 5 corrects the image data so as to enlarge the surface shape of the recording medium S indicated by the image data. Note that the second threshold value is set based on the curvature radius R of the virtual circumferential surface in which the plurality of nozzles 43 are arranged in the circumferential direction, the arrangement pitch of the plurality of nozzles 43, and the pixel pitch of the pixels indicated by the image data. Specifically, for example, when the nozzles 43 are arranged at an arrangement pitch n times the pixel pitch of the pixels indicated by the image data, the second threshold value is represented by an expression of (2n−1) R / 2n. . The control unit 5 associates each position on the surface of the recording medium S indicated by the position data with each pixel position in the three-dimensional shape indicated by the corrected image data.

  In addition, the control unit 5 determines a nozzle 43 that does not eject ink when the distance L is larger than the second threshold and smaller than the distance between the nozzle 43 that ejects ink and the first axis 13. To do. In other words, the control unit 5 thins out the nozzles 43 that discharge ink among the plurality of nozzles 43. Specifically, when the distance L is greater than (2n−1) R / 2n, ink is ejected from one nozzle 43 per two. In addition, when the distance L is greater than (mn−1) R / mn, ink is ejected from one nozzle 43 per m. Here, m is a positive integer of 2 or more.

  In the image forming apparatus 1 of the present embodiment, the image data is corrected based on the distance L, or the nozzles 43 that discharge ink from the plurality of nozzles 43 are thinned out. Therefore, even when the distance between the nozzle 43 that ejects the ink and the surface of the recording medium S is longer than the first threshold, it is possible to prevent the ink from being excessively supplied to the surface of the recording medium S.

  Further, for example, when there are a plurality of operation patterns of the recording head 42 capable of forming an image on the recording medium S, the control unit 5 selects an operation pattern having the shortest operation time from among the plurality of operation patterns.

  The control unit 5 controls the image forming unit 4 to form an image on the recording medium S based on the selected operation pattern of the recording head 42. For example, the controller 5 forms an image on the recording medium S by repeating the movement process and the ejection process of the recording head 42. In the movement process, the control unit 5 moves the recording head 42 according to the selected operation pattern. In addition, the control unit 5 causes ink to be ejected from the nozzle 43 that has moved to the ejection position in the ejection process.

  Further, in the ejection process of the recording head 42, the control unit 5 determines whether or not the ink droplet deposition position of each nozzle 43 is a position exceeding the first axis 13 when ejecting ink from the plurality of nozzles 43. judge. When it is determined that the ink landing position of each nozzle 43 exceeds the first axis 13, the control unit 5 controls each nozzle 43 so that a deviation occurs in the ink ejection timing. As a result, ink ejected from the plurality of nozzles 43 can be prevented from contacting on the first axis 13.

  In the image forming apparatus 1 of the present embodiment, ink ejected from each of the plurality of nozzles 43 in a non-parallel direction adheres to the recording medium S. Therefore, the ink can be supplied to the surface of the recording medium S without excess and deficiency, and the density of the ink adhering to the surface of the recording medium S can be made constant. As a result, distortion of the image formed on the three-dimensional recording medium S can be suppressed.

  Next, an image forming process performed by the control unit 5 will be described with reference to FIGS. FIG. 5 is a flowchart showing image forming processing by the control unit 5. As illustrated in FIG. 5, the control unit 5 starts an image forming process for forming an image on the recording medium S based on an operation signal input from the operation unit 6. In this embodiment, before the operation signal is input to the control unit 5, the recording medium S is mounted on the mounting table 12, and image data is input from the external input device 7 to the control unit 5. .

  When the operation signal is input, the control unit 5 controls the position information generation unit 3 to image the recording medium S in step S10. When the position information is input from the position information generating unit 3, the control unit 5 generates position data indicating the position of the surface of the recording medium S in step S20.

  When the position data is generated, the control unit 5 specifies the ink landing position based on the position data and the image data in step S30. After specifying the ink landing position, the control unit 5 selects a nozzle 43 that ejects ink for each pixel of the recording medium S in step S40. After selecting the nozzle 43, the control unit 5 performs a movement process and a discharge process so as to form an image on the recording medium S in step S50.

[Embodiment 2]
Next, the configuration of the image forming apparatus 1 according to the second embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a side view showing the image forming apparatus 1 according to the second embodiment of the present invention. FIG. 7 is a plan view of the image forming apparatus 1 according to the second embodiment of the present invention.

  The image forming apparatus 1 according to the second embodiment is different from the image forming apparatus 1 according to the first embodiment in that the holder supporting portion 2 is not provided and the columnar supporting portion 8 is provided. The image forming apparatus 1 according to the second embodiment is different from the image forming apparatus 1 according to the first embodiment in the shapes of the camera holder 31 and the head holder 41.

  The columnar support portion 8 is disposed on the upper surface portion of the base portion 11. Specifically, the columnar support portion 8 is disposed at the edge of the upper surface portion of the base portion 11. The columnar support portion 8 is formed in a column shape extending upward from the upper surface portion of the base portion 11. The columnar support unit 8 supports the camera holder 31 of the position information generation unit 3 and the head holder 41 of the image forming unit 4 so as to be movable up and down.

  In the present embodiment, the camera holder 31 is formed in an annular shape. Specifically, the camera holder 31 is formed in an annular shape centered on the first axis 13. The camera holder 31 is moved up and down along the first axis 13 by a predetermined lifting unit housed inside the columnar support 8. The camera holder 31 holds the plurality of imaging elements 32 described with reference to FIG. The predetermined elevating unit includes, for example, a support member that supports the camera holder 31, a moving mechanism that moves the support member in the vertical direction, and a drive source that supplies power to the moving mechanism.

  In the present embodiment, the head holder 41 is formed in an annular shape. Specifically, the head holder 41 is formed in an annular shape centered on the first axis 13. The head holder 41 is moved up and down along the first axis 13 by a predetermined lifting unit housed inside the columnar support 8. The head holder 41 moves up and down independently of the camera holder 31. The head holder 41 holds the plurality of nozzles 43 described with reference to FIG. 3 in an annular shape. The predetermined elevating unit includes, for example, a support member that supports the head holder 41, a moving mechanism that moves the support member in the vertical direction, and a drive source that supplies power to the moving mechanism.

  The mounting table 12 is rotated by, for example, a predetermined driving unit accommodated in the base unit 11. Specifically, the mounting table 12 is rotated around the first axis 13. The predetermined drive unit includes, for example, a rotation mechanism that rotates the mounting table 12 and a power source that supplies power to the rotation mechanism.

  For example, the control unit 5 controls the position information generation unit 3 to generate position information on the surface of the recording medium S based on an operation signal input from the operation unit 6. Specifically, the control unit 5 operates the mounting table 12 and the camera holder 31 and causes the plurality of imaging elements 32 to image the recording medium S. Here, the operation of the mounting table 12 includes rotation around the first axis 13. The operation of the camera holder 31 includes raising and lowering along the first axis 13. As a result, position information is input to the control unit 5 from the position information generation unit 3.

  Further, the control unit 5 determines the operation pattern of the mounting table 12 and the recording head 42 based on the image data and the position data. The operation pattern of the mounting table 12 includes rotation around the first axis 13. The operation pattern of the recording head 42 includes raising and lowering along the first axis 13.

  Based on the image data and the position data, the control unit 5 specifies the ink landing position, selects the nozzle 43 that ejects the ink, and determines the operation patterns of the mounting table 12 and the recording head 42. For example, when there are a plurality of operation patterns capable of forming an image on the recording medium S, the control unit 5 selects an operation pattern having the shortest operation time among the plurality of operation patterns.

  The control unit 5 controls the image forming unit 4 to form an image on the recording medium S. For example, the controller 5 forms an image on the recording medium S by repeating the movement process of the mounting table 12 and the recording head 42 and the ejection process of the recording head 42. In the movement process, the control unit 5 moves the mounting table 12 and the recording head 42 according to the determined operation pattern. In addition, the control unit 5 causes ink to be ejected from the nozzle 43 that has moved to the ejection position in the ejection process.

  In the image forming apparatus 1 according to the second embodiment of the present invention, the ink ejected from each of the plurality of nozzles 43 in the non-parallel direction is the recording medium S, as in the image forming apparatus 1 according to the first embodiment of the present invention. Adhere to. Therefore, the ink can be supplied to the surface of the recording medium S without excess and deficiency, and the density of the ink adhering to the surface of the recording medium S can be made constant. As a result, distortion of the image formed on the three-dimensional recording medium S can be suppressed.

[Embodiment 3]
Next, the configuration of the image forming apparatus 1 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a side view showing the image forming apparatus 1 according to Embodiment 3 of the present invention.

  The image forming apparatus 1 according to the third embodiment is different from the image forming apparatus 1 according to the first embodiment in that the holder support portion 2 further includes a third axis 15. The image forming apparatus 1 according to the third embodiment is different from the image forming apparatus 1 according to the first embodiment in the shapes of the camera holder 31 and the head holder 41. The image forming apparatus 1 according to the third embodiment is different from the image forming apparatus 1 according to the first embodiment in that the holder support portion 2 includes a first support portion 2a and a second support portion 2b.

  The upper surface portion of the mounting table 12 is formed in a concave shape that is recessed inside the mounting table 12. On the mounting table 12, for example, a sheet-like recording medium S is mounted so as to correspond to the shape of the upper surface portion.

  The holder support part 2 further includes a third axis 15 in addition to the second axis 14. The third axis 15 extends along the horizontal direction Y. The third axis 15 is orthogonal to the first axis 13. The holder support unit 2 includes a first support unit 2 a that supports the image forming unit 4 and a second support unit 2 b that supports the position information generation unit 3. The first support portion 2 a has a first rotation shaft 22. The second support part 2 b has a second rotation shaft 23.

  In this embodiment, the 1st rotating shaft 22 is rotated by the predetermined drive part which the 1st support part 2a has, for example. The predetermined drive unit includes, for example, a rotation mechanism that rotates the first rotation shaft 22 around the second axis 14 and a power source that supplies power to the rotation mechanism. Moreover, in this embodiment, the 2nd rotating shaft 23 is rotated by the predetermined drive part which the 2nd support part 2b has, for example. The predetermined drive unit includes, for example, a rotation mechanism that rotates the second rotation shaft 23 around the third axis 15 and a power source that supplies power to the rotation mechanism.

  The head holder 41 is formed in an arc shape. Specifically, the head holder 41 holds the plurality of nozzles 43 described with reference to FIG. 3 in an arc shape. In the present embodiment, the head holder 41 holds a plurality of nozzles 43 so as to eject ink from the center of the arc toward the outside.

  In the present embodiment, the camera holder 31 is formed in an arc shape. Specifically, the camera holder 31 holds the plurality of imaging elements 32 described with reference to FIG. 3 in an arc shape. In the present embodiment, the camera holder 31 holds a plurality of imaging elements 32 so as to face outward from the center of the arc.

  In the image forming apparatus 1 according to the third embodiment of the present invention, the ink ejected from each of the plurality of nozzles 43 in a non-parallel direction is a sheet-like shape, as in the image forming apparatus 1 according to the first embodiment of the present invention. It adheres to the recording medium S. Therefore, the ink can be supplied to the surface of the recording medium S without excess and deficiency, and the density of the ink adhering to the surface of the recording medium S can be made constant. As a result, distortion of the image formed on the three-dimensional recording medium S can be suppressed.

  In the present embodiment, the rotation unit 21 may rotate the first support unit 2a and the second support unit 2b independently. Moreover, the raising / lowering part 24 may raise / lower the 1st support part 2a and the 2nd support part 2b independently.

  The image forming apparatus 1 according to the first embodiment of the present invention, the second embodiment of the present invention, and the third embodiment of the present invention has been described above with reference to FIGS. However, the present invention is not limited to the first embodiment, the second embodiment, and the third embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, in the embodiment of the present invention, the appearance of the recording medium S is imaged by the plurality of imaging elements 32, but the present invention is not limited to this. The position information generation unit 3 may output the position information of the recording medium S placed on the mounting table 12 to the control unit 5. For example, the position information generation unit 3 may include a plurality of distance measuring sensors instead of the plurality of imaging elements 32. The position information generation unit 3 outputs distance information indicating the distance from the distance measuring sensor to the recording medium S as position information to the control unit 5 based on the distance to the recording medium S measured by the plurality of distance measuring sensors. . The control unit 5 can identify the position of the surface of the recording medium S based on the distance information, and can acquire the position data of the recording medium S placed on the mounting table 12.

  In the embodiment of the present invention, the camera holder 31 and the head holder 41 are formed in an arc shape or an annular shape, and the plurality of imaging elements 32 and the plurality of nozzles 43 are held in an arc shape or an annular shape. The invention is not limited to this. The plurality of imaging elements 32 and the plurality of nozzles 43 may be held non-parallel by the camera holder 31 or the head holder 41.

  In the embodiment of the present invention, the recording heads 42y, 42c, 42m, and 42k are held side by side in the thickness direction of the head holder 41, but the present invention is not limited to this. With reference to FIG. 9, another embodiment of the present invention will be described. FIG. 9 is a diagram showing an image forming unit 4 according to another embodiment of the present invention. Specifically, FIG. 9 is a diagram illustrating a part of the image forming unit 4.

  In the image forming unit 4 shown in FIG. 9, all the nozzles 43 are arranged in the circumferential direction of the head holder 41. The image forming unit 4 includes a plurality of nozzle units 45. The nozzle unit 45 includes, for example, a nozzle 43y that discharges yellow ink, a nozzle 43c that discharges cyan ink, a nozzle 43m that discharges magenta ink, and a nozzle 43k that discharges black ink. Have The nozzles 43 are arranged in an arc shape. The plurality of nozzle units 45 are arranged in an arc shape. In the embodiment shown in FIG. 9 as well, the same effects as those of the image forming apparatus 1 described with reference to FIGS. 1 to 8 can be obtained. The nozzle units 45 may be arranged in a staggered manner along the circumferential direction.

  In the embodiment of the present invention, image data is generated in advance, but the present invention is not limited to this. For example, the position information output from the position information generation unit 3 may be input to the external input device 7 and the external input device 7 may generate the image data based on the position information.

  In order to facilitate understanding, the drawings schematically show each component mainly, and the thickness, length, etc. of each component shown in the drawings are different from the actual for convenience of drawing. . Moreover, the shape of each component shown by said embodiment is an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the effect of this invention.

  The present invention can be used in an image forming apparatus that forms an image on a three-dimensional recording medium.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Image forming part 41 Head holder 42 Recording head 43 Nozzle S Recording medium

Claims (17)

An image forming unit that forms an image on a three-dimensional recording medium;
The image forming unit includes at least one recording head that forms an image with ink on the recording medium, and a head holder that holds the recording head,
The recording head has a plurality of nozzles,
At least one nozzle among the plurality of nozzles ejects ink in a direction non-parallel to a direction in which the other nozzle ejects ink.   The image forming apparatus according to claim 1, wherein the plurality of nozzles are arranged in an arc shape or an annular shape, and eject the ink toward the center of the arc. A mounting table on which the recording medium is mounted; and a first support unit that supports the image forming unit;
The mounting table includes an upper surface portion extending along a horizontal direction, and a first axis extending through the center of the upper surface portion and extending in the vertical direction.
The first support portion has a second axis perpendicular to the first axis, and a first rotation axis extending along the second axis.
The first rotation shaft rotates about the second axis;
The image forming apparatus according to claim 2, wherein the head holder is supported by the first rotation shaft.   The image forming apparatus according to claim 3, wherein the head holder is formed in an arc shape or an annular shape, and pivots around the second axis outside the recording medium. The first support portion further includes a first rotating portion that rotates around the first axis outside the recording medium,
The image forming apparatus according to claim 3, wherein the first rotating unit supports the first rotating shaft.   The image forming apparatus according to claim 5, wherein the first support part further includes a first elevating part that elevates and lowers the first rotating part along the first axis.   The image forming apparatus according to claim 1, wherein the mounting table is disposed inside the head holder.   The image forming apparatus according to claim 7, further comprising a base portion that supports the mounting table such that the first axis passes through the center of the mounting table. A position information generating unit that generates position information indicating the position of the surface of the recording medium;
A control unit for controlling the image forming unit,
The controller is
9. The image forming unit according to claim 1, wherein the image forming unit is controlled to form an image on the recording medium based on the position information and image data indicating an image to be formed on the recording medium. The image forming apparatus described in 1. The position information generation unit includes a plurality of detection units that detect reflected light from the recording medium, and a detection unit holder that holds the plurality of detection units.
The image formation according to claim 9, wherein at least one of the plurality of detection units detects the reflected light from a direction non-parallel to a direction in which the other detection unit detects the reflected light. apparatus.   The image forming apparatus according to claim 10, wherein the plurality of detection units are arranged in an arc shape or an annular shape. A mounting table on which the recording medium is mounted; and a second support unit that supports the position information generation unit,
The mounting table includes an upper surface portion extending along a horizontal direction, and a first axis extending through the center of the upper surface portion and extending in the vertical direction.
The second support portion has a third axis orthogonal to the first axis, and a second rotation axis extending along the third axis,
The second rotating shaft rotates about the third axis;
The image forming apparatus according to claim 11, wherein the detection unit holder is supported by the second rotation shaft.   The image forming apparatus according to claim 12, wherein the detection unit holder is formed in an arc shape or an annular shape, and rotates outside the recording medium around the third axis. The second support part further includes a second rotating part that rotates the outside of the recording medium around the first axis,
The image forming apparatus according to claim 12, wherein the second rotating unit supports the second rotating shaft.   The image forming apparatus according to claim 14, wherein the second support part further includes a second elevating part that elevates and lowers the second rotating part along the first axis. The detection unit includes an image sensor that images the recording medium,
The image forming apparatus according to claim 10, wherein the imaging element generates imaging information indicating the captured recording medium as the position information. The detection unit includes a distance measuring sensor,
The image forming apparatus according to any one of claims 10 to 16, wherein the distance sensor generates distance information indicating a distance between the distance sensor and the recording medium as the position information.

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