JP7024170B2 - Inkjet printer - Google Patents

Description

Embodiments of the present invention relate to inkjet printers.

The inkjet printer ejects a droplet of ink from an inkjet head to print an image on a printed matter. Since the inkjet printer can print an image without contacting the object to be printed, it is possible to print not only a sheet-like object such as printing paper but also a soft object such as food and drink. As a specific example, there is an inkjet printer that realizes latte art that draws a pattern with milk on the surface of espresso or coffee poured into a cup.

In recent years, latte art has been provided in which an image is printed with edible ink on the surface of frothed milk that covers the liquid surface of espresso. However, the surface of the frothed milk is not always flat. If the gap from the inkjet head to the surface of the foamed milk is non-uniform, the ejected ink droplets may not fly to the target position and the printing may be disturbed where the gap is large. Further, if the gap is too narrow, the nozzle surface for ejecting ink may come into contact with foaming milk, resulting in ejection failure.

Japanese Unexamined Patent Application Publication No. 2015-142699 Japanese Unexamined Patent Publication No. 2017-110178 Japanese Patent Publication No. 2007-526765

An object to be solved by the present invention is to provide an inkjet printer capable of making a three-dimensional soft object a printable object and suppressing printing disturbance.

In order to solve the above problems, the inkjet printer of the embodiment includes a spatula-shaped surface preparation member , an inkjet head , a printed matter detection sensor, and a control unit . The spatula-shaped surface preparation member pushes through a part of the three-dimensional printed matter. The inkjet head ejects ink onto the printing target surface of the printed matter that has been prepared by being pushed by the surface-adjusting member. The printed matter detection sensor detects the height of the printed matter. The control unit determines the height at which the surface preparation member pushes through the printed matter based on the result detected by the printed matter detection sensor.

Further, the inkjet printer of another embodiment includes a surface preparation member and an inkjet head. The surface preparation member sucks while pushing off a part of the three-dimensional printed matter. The inkjet head ejects ink onto the printing target surface of the printed matter whose surface is prepared by suction.

It is a perspective view which shows the whole structure of the inkjet printer of 1st Embodiment. It is a perspective view which shows the schematic structure of the inkjet head of the inkjet printer of 1st Embodiment. It is a block diagram of the control system of the inkjet printer of 1st Embodiment. It is a flowchart which shows the process of printing an image on the printed matter by the inkjet printer of 1st Embodiment. It is explanatory drawing of the process of detecting the height of the printed matter by the printed matter detection sensor of the inkjet printer of 1st Embodiment. It is explanatory drawing explaining the height information detected by the printed matter detection sensor of the inkjet printer of 1st Embodiment. It is explanatory drawing of the process which the surface preparation member of the inkjet printer of 1st Embodiment prepares a surface of a printed matter. It is explanatory drawing of the process which the inkjet head of the inkjet printer of 1st Embodiment prints an image on the print target surface of a printed matter. It is explanatory drawing of the process which the inkjet head of the inkjet printer of 1st Embodiment prints an image on the print target surface of a printed matter. It is explanatory drawing of the process which the inkjet head of the inkjet printer of 1st Embodiment prints an image on the print target surface of a printed matter. It is explanatory drawing which shows the other example of the print object which the inkjet printer of 1st Embodiment prints an image. It is explanatory drawing which shows the other example of the print object which the inkjet printer of 1st Embodiment prints an image. It is explanatory drawing which shows the other example of the print object which the inkjet printer of 1st Embodiment prints an image. It is a perspective view which shows the other example of the surface preparation member of the inkjet printer of 1st Embodiment. It is a perspective view which shows the schematic structure of the inkjet printer of 2nd Embodiment. It is explanatory drawing of the process which the surface preparation member of the inkjet printer of 2nd Embodiment prepares a surface of a printed matter. It is a block diagram of the control system of the inkjet printer of 2nd Embodiment.

Hereinafter, the inkjet printer according to the embodiment will be described in detail with reference to the attached drawings. In each figure, the same configurations are designated by the same reference numerals.

(First Embodiment)
FIG. 1 shows, as an example of the inkjet printer 1 according to the first embodiment, the overall configuration of a food printer in which food and drink are printed matter and an image is printed on the surface thereof. FIG. 2 shows a schematic configuration of an inkjet head 2 included in the inkjet printer 1. FIG. 3 is a block diagram of the control system of the inkjet printer 1.

FIG. 1 illustrates a foaming milk (foam-like material) 12 that covers the liquid surface of espresso poured into a cup 11 as an example of a three-dimensional printed matter 10. In this case, the inkjet printer 1 provides latte art that ejects edible ink and prints an image on the surface of the frothed milk 12. For example, drawing a pattern on coffee may be referred to as coffee art, or printing a photograph taken with a mobile terminal may be referred to as photo latte, but the "latte art" referred to in the present embodiment may be used. "Includes these without distinction.

The inkjet printer 1 includes, for example, a main body portion 3 having an exterior formed of a resin material. The stage 31 on which the printed matter 10 is installed, the X stage 32 for moving the stage 31 in the X direction (left-right direction), and the Y stage 33 for moving the stage 31 in the Y direction (front-back direction) are arranged on the upper surface of the main body 3. is doing. The stage 31 is, for example, a rectangular flat plate made of a resin material. For example, the central portion of the surface of the stage 31 may be marked with a mark as a mark when the user places the printed matter 10.

The X stage 32 extending in the X direction includes an X-axis linear scale 34 for detecting the coordinate position of the stage 31 in the X direction, and an X-axis motor 35 as a driving device for sliding the stage 31 in the X direction (FIG. 3). reference). The stage 31 is moved, for example, by driving a ball screw (not shown) with an X-axis motor 35. The Y stage 33 extending in the Y direction includes a Y-axis linear scale 36 for detecting the coordinate position of the stage 31 in the Y direction, and a Y-axis motor 37 as a driving device for sliding the stage 31 in the Y direction (FIG. 3). reference). The stage 31 is moved, for example, by driving a ball screw (not shown) with a Y-axis motor 37.

The inkjet head 2 for ejecting edible ink is supported by an upright portion 3A of the main body portion 3 via a Z1 stage 21 which is a first Z stage. The Z1 stage 21 is an elevating device that moves the inkjet head 2 in the Z direction. The Z1 stage 21 includes a Z1-axis linear scale 22 for detecting the coordinate position of the inkjet head 2 in the Z direction, and a Z1-axis motor 23 as a driving device for raising and lowering the inkjet head 2 in the Z direction (see FIG. 3). The movement of the inkjet head 2 in the Z direction is performed, for example, by driving a ball screw (not shown) with a Z1-axis motor 23.

The ink tank 24 for storing edible ink is arranged, for example, in the upright portion 3A of the main body portion 3. The ink tank 24 and the inkjet head 2 communicate with each other via the ink supply path 25. The ink supply path 25 is, for example, a flexible tube made of a resin material. The liquid edible ink stored in the ink tank 24 is supplied to the inkjet head 2 by the ink supply pressure adjusting device 26, which is an example of the liquid feeding device. The ink may be circulated between the ink tank 24 and the inkjet head 2. Edible ink is an ink based on the Food Sanitation Law, which uses food coloring as a coloring material and all components are composed of foods, food additives, and the like. A plurality of inkjet heads 2 may be arranged, and color printing may be performed using cyan (C), magenta (M), yellow (Y), and black (BK) inks. Further, the ink tank 24 may be a detachable cartridge type.

The inkjet head 2 may be either an on-demand inkjet head or a continuous inkjet head. 1 and 2 show an on-demand inkjet head 2. As a preferable example, the on-demand type inkjet head 2 includes a piezo type, a share wall type, or a share mode type ejection type actuator. Since it is an edible ink, it is desirable to cover the drive electrode of the actuator with an insulating material from the viewpoint of safety and hygiene. Further, it is desirable to use an actuator in which the piezoelectric element is formed of a lead-free piezoelectric material.

The inkjet head 2 has a substantially rectangular outer shape, and is arranged so that its long side is along the X direction. As an example, the size of the inkjet head 2 is 80 to 90 mm in length in the X direction, 60 to 70 mm in width in the Y direction, and 20 to 30 mm in height in the Z direction. As shown in FIG. 2, the inkjet head 2 has a plurality of nozzles 28, which are ejection holes, arranged on a nozzle plate 27 arranged on the bottom surface. The nozzle density is, for example, in the range of 150 to 1200 dpi.

The nozzle plate 27 is made of a metal such as stainless steel. In the case of latte art, a heater 29 may be arranged as an example of a cleaning member on the upper surface side of the nozzle plate 27, for example. The heater 29, for example, by heating the nozzle plate 27 during printing, suppresses condensation of steam of espresso on the surface of the nozzle plate 27, for example. Alternatively, by heating the nozzle plate 27 after printing is completed, the dew condensation on the surface of the nozzle plate 27 is evaporated. As another example of the cleaning member, a drying device that blows a gas such as air toward the surface of the nozzle plate 27 after printing may be provided on the side surface of the inkjet head 2, for example.

The printed matter detection sensor 4 is arranged on the side surface of the long side of the inkjet head 2 located on the front side. The position of the printed matter detection sensor 4 in the X direction is preferably the center of the long side of the inkjet head 2. The printed matter detection sensor 4 detects the installation position of the printed matter 10 on the stage 31, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10. Although a specific example will be described later, the installation position of the printed matter 10 on the stage 31 and the printed matter are detected by scanning the printed matter detection sensor 4 and detecting the distance to the printed matter 10 in association with the X coordinate and the Y coordinate. The contour of 10 in a plan view and the height of the printed matter 10 are detected. The printed matter detection sensor 4 uses, for example, an infrared distance sensor including a light emitting element and a light receiving element. The printed matter detection sensor 4 is not limited to one, and a plurality of printed matter detection sensors 4 may be arranged on the long side of the inkjet head 2.

The surface preparation member 5 that cuts out an unnecessary portion of the printed matter 10 to prepare the surface to be printed is supported by the upright portion 3A of the main body portion 3 via the Z2 stage 51 which is the second Z stage. .. The surface preparation member 5 is preferably arranged on the front side in the Y direction with respect to the inkjet head 2. The Z2 stage 51 is an elevating device that moves the surface preparation member 5 in the Z direction. The Z2 stage 51 includes a Z2-axis linear scale 52 that detects the coordinate position of the surface preparation member 5 in the Z direction, and a Z2-axis motor 53 as a drive device that moves the surface preparation member 5 in the Z direction (see FIG. 3). ). The surface preparation member 5 is moved, for example, by driving a ball screw (not shown) with a Z2-axis motor 53.

The surface preparation member 5 is, for example, a plate-shaped member and is used as a spatula. That is, it is a spatula-shaped surface preparation member 5. The surface preparation member 5 has a rectangular shape in a plan view and is arranged so that its long side is along the X direction. The surface preparation member 5 is arranged in an inclined posture in which the bottom surface 54 and the top surface 55 are inclined upward from the front side to the rear side. Further, on the front side of the upper surface 55, an inclined surface 55a having a larger inclination than the rear side is formed. As an example, the size of the surface preparation member 5 is 100 to 120 mm in length in the X direction, 80 to 90 mm in width in the Y direction, and 1 to 5 mm in thickness in the Z direction. The inclination angle of the bottom surface 54 and the top surface 55 is, for example, within 5 °. The material of the surface preparation member 5 is, for example, a resin material such as fluororesin or a metal material such as stainless steel.

Further, since the surface preparation member 5 cuts out an unnecessary portion of the printed matter 10 and prepares the surface, the drawing is omitted, but a collection unit (for example, a collection container) for collecting the cut out printed matter 10 and a surface preparation member 5 A cleaning device for cleaning by spraying cleaning water such as tap water may be provided on the main body 3.

The operation unit 6 in which the user operates the inkjet printer 2 is arranged in front of the upright portion 3A of the main body unit 3. The operation unit 6 is, for example, a touch panel display. The user operates the operation unit 6 to start / stop the inkjet printer 1, select a print menu, and the like. The creation / selection of the image to be printed, the execution of the print job, and the like may be performed from an external information terminal such as a personal computer (PC) or a mobile terminal.

The control unit 7 that controls the printing operation of the inkjet printer 1 is arranged inside the upright portion 3A of the main body unit 3. As shown in FIG. 3, the control unit 7 of the inkjet printer 1 includes a CPU 71, a ROM 72, and a RAM 73. The CPU 71 reads information such as a program and various control conditions from the ROM 72 to control the overall operation of the inkjet printer 1. The ROM 72 stores data of various control conditions such as programs and set values. The RAM 73 is a work area for temporarily storing information from, for example, various detection circuits when the CPU 71 executes a program stored in the ROM 72. The CPU 71, ROM 72, and RAM 73 are computers that form the core of the control unit 7. Each configuration in the control unit 7 is connected by a bus line 74.

The control unit 7 includes an X-axis drive circuit 75, a Y-axis drive circuit 76, a Z1-axis drive circuit 77, and a Z2-axis drive circuit 78. The X-axis drive circuit 75, the Y-axis drive circuit 76, the Z1-axis drive circuit 77, and the Z2-axis drive circuit 78 are drive system devices such as the X-axis motor 35, the Y-axis motor 37, the Z1-axis motor 23, and the Z2-axis motor, respectively. It is electrically connected to 53. The CPU 71 sends time-series position data of the stage 31 and the inkjet head 2 or the stage 31 and the surface preparation member 5 to the X-axis drive circuit 75, the Y-axis drive circuit 76, the Z1-axis drive circuit 77, and the Z2-axis drive circuit 78. .. The X-axis drive circuit 75, the Y-axis drive circuit 76, the Z1-axis drive circuit 77, and the Z2-axis drive circuit 78 have an X-axis motor 35, a Y-axis motor 37, a Z1-axis motor 23, and a Z2-axis based on time-series position data. It controls operations such as starting and stopping of the motor 53.

The control unit 7 includes an X coordinate position detection circuit 81, a Y coordinate position detection circuit 82, a Z1 coordinate position output circuit 83, and a Z2 coordinate position detection circuit 84. The X-coordinate position detection circuit 81, the Y-coordinate position detection circuit 82, the Z1 coordinate position output circuit 83, and the Z2 coordinate position detection circuit 84 are sensor-based devices such as the X-axis linear scale 34, the Y-axis linear scale 36, and the Z1 axis, respectively. It is communicably connected to the linear scale 22 and the Z2-axis linear scale 52.

The X-coordinate position detection circuit 81 detects the X-coordinate of the stage 31 by counting the pulse signal output from the X-axis linear scale 34. The Y coordinate position detection circuit 82 detects the Y coordinate of the stage 31 by counting the pulse signal output from the Y axis linear scale 36. The Z1 coordinate position detection circuit 83 detects the Z coordinate on the surface of the nozzle plate 27 of the inkjet head 2 by counting the pulse signal output from the Z1 axis linear scale 22. The Z2 coordinate position detection circuit 84 detects the Z coordinate of the bottom surface 54 of the surface preparation member 5 by counting the pulse signal output from the Z2-axis linear scale 52. The CPU 71 aligns the stage 31, the inkjet head 2, and the stage 31 based on the coordinates detected by the X coordinate position detection circuit 81, the Y coordinate position detection circuit 82, the Z1 coordinate position output circuit 83, and the Z2 coordinate position detection circuit 84. The three-dimensional relative positional relationship of the surface member 5 is detected. Further, the CPU 71 generates time-series position data of the stage 31, the inkjet head 2, and the stage 31 and the surface preparation member 5 at the time of printing, and drives the X-axis drive circuit 75, the Y-axis drive circuit 76, and the Z1 axis. Output to the circuit 77 and the Z2-axis drive circuit 78, respectively.

The control unit 7 includes a printed matter detection sensor position detection circuit 41. The printed matter detection sensor position detection circuit 41 is communicably connected to the printed matter detection sensor 4. The CPU 71 controls the X stage 32 and the Y stage 33 to sequentially move the stage 31 back and forth and left and right to scan the printed matter detection sensor 4. The printed matter detection sensor position detection circuit 41 detects the height of the printed matter 10 in the Z direction based on the information from the printed matter detection sensor 4.

The control unit 7 includes an image memory 85 that temporarily stores image data to be printed on the printed matter 10. The image data is received from an external information terminal 9 connected so as to be capable of information communication via, for example, an interface (I / F) 86. The external information terminal 9 is, for example, a personal computer (PC) or a mobile terminal. When the CPU 71 receives the image data from the external information terminal 9, the CPU 71 outputs the received image data to the image memory 85. Further, the CPU 71 outputs the image data to the image transfer circuit 87. The image transfer circuit 87 rearranges the image data into image data synchronized with the time-series position data of the stage 31 and the inkjet head 2 controlled at the time of printing, and transfers the rearranged image data to the inkjet head 2. The image is transferred, for example, through an image transfer cable. A plurality of image data may be stored in the ROM 72 in advance, and the user may select from, for example, a plurality of image data displayed on the operation unit 6.

The inkjet head 2 operates an actuator based on time-series ejection data from the image transfer circuit 87, and ejects ink from a predetermined nozzle 28 of the nozzle plate 27, or controls the amount of ejected ink and the number of ejections. Discharge droplets.

Subsequently, the flow of the process in which the inkjet printer 2 prints an image on the printed matter 10 will be described with reference to FIGS. 4 to 10.

After installing the printed matter 10 on the stage 31, the user operates, for example, the operation unit 6 to cause the inkjet printer 2 to execute a print job (Act 10). The image to be printed is transmitted from the external information terminal 9. Alternatively, the user selects from the images stored in advance in the inkjet printer 2. The operation of executing the print job may be performed from the external information terminal 9.

In the case of latte art, the printed matter 10 is obtained by pouring espresso into the cup 11 and then pouring the frothed milk 12. When installed on the stage 31, the frothed milk 12 may be in a state of rising above the edge of the cup 11.

Subsequently, the control unit 7 determines whether the printed matter 10 is in a predetermined position or a free position (Act 11). That is, the position where the user installs the printed matter 10 on the stage 31 is predetermined on the stage 31 in consideration of the relative movement range and movement time in the X direction and the Y direction of the inkjet head 2 and the surface preparation member 5. It is desirable that the position is set. However, for example, it is determined whether the printed matter 10 is in a predetermined position or a free position so that printing can be performed even if the printed matter 10 is installed at a position deviating from a predetermined position. Further, it is determined whether the cup 11 is in a predetermined position or a free position so that printing can be performed even if the cups 11 having different sizes and shapes are used.

As an example, the printed matter detection sensor 4 is used to determine whether the position is in a predetermined position or in a free position. The control unit 7 raises the inkjet head 2 to, for example, an upper limit position so as not to collide with the printed matter 10, and then moves the stage 31 to move the printed matter detection sensor 4 to a predetermined position (for example, above the center of the stage 31). To be located in. Then, the control unit 7 detects whether or not the printed matter 10 is present below by using the printed matter detection sensor 4. That is, when the distance detected by the printed matter detection sensor 4 is shorter than the distance from the printed matter detection sensor 4 to the stage 31, it is determined that the printed matter 10 is below (Act 11, predetermined position). On the other hand, when the distance detected by the printed matter detection sensor 4 matches the distance from the printed matter detection sensor 4 to the stage 31, it is determined that there is no printed matter 10 below (Act 11, free position).

When the position is predetermined, the control unit 7 sets the scanning range of the printed matter detection sensor 4 to the predetermined range of the stage 31 (Act 12). Specifically, the control unit 7 receives height information from the printed matter detection sensor 4 while sequentially moving the stage 31 back and forth and left and right from the position where the printed matter 10 is detected, and receives the height information from the printed matter detection sensor 4, and the X-axis linear scale 34 and the Y-axis linear scale. By associating the information of the X-axis coordinate and the Y-axis coordinate from 36, the information on the installation position of the printed matter 10 on the stage 31, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10 is acquired ( Act14). The control unit 7 may perform analysis of the installation position of the printed matter 10 on the stage 31, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10, and is an external information terminal operated by the user. 9 may do so.

FIG. 5 shows how the printed matter detection sensor 4 is scanned by moving the inkjet head 2 in the horizontal direction. FIG. 6 shows the height information obtained by scanning the printed matter detection sensor 4 in a waveform. When the printed matter detection sensor 4 scans on the center line of the cup 11 as shown in FIG. 6A, when the cross-sectional shape of the printed matter 10 is FIG. 6B, the height information is shown by, for example, a waveform 100 in FIG. It becomes like (c). That is, the waveform 100 rises from the height of the upper surface of the stage 31 to the height of the edge of the cup 11, and becomes flat at the edge of the cup 11. Then, after the height fluctuates along the surface of the frothed milk 12, a flat waveform appears at the edge portion of the cup 11 on the opposite side, and finally returns to the height of the upper surface of the stage 31. The edge portion of the cup 11 shows the contour of the printed matter 10 in a plan view. When the printed matter detection sensor 4 is scanned for the entire range of the printed matter 10, for example, the installation position of the printed matter 10 on the stage 31, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10 Information can be obtained. However, in order to shorten the time, the number of scans may be reduced by increasing the scan interval in the X direction. Alternatively, as shown in FIG. 6A, scanning may be performed only on the center line of the cup 11.

On the other hand, when the position is free, the control unit 7 sets the scanning range of the printed matter detection sensor 4 to the entire range of the stage 31 (Act 13). Specifically, the control unit 7 moves the stage 31 so that the printed matter detection sensor 4 is located above one end (for example, a corner) of the stage 31, and then sequentially moves the stage 31 back and forth and left and right. The printed matter detection sensor 4 is scanned to the other end of the stage 31 (for example, a diagonal corner). Then, by associating the height information sequentially received from the printed matter detection sensor 4 with the information of the X-axis coordinates and the Y-axis coordinates from the X-axis linear scale 34 and the Y-axis linear scale 36, the printed matter 10 on the stage 31 Information on the installation position, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10 is acquired (Act 14).

Subsequently, the control unit 7 scans the surface preparation member 5 in the horizontal direction based on the acquired information on the installation position of the printed matter 10, the contour of the printed matter 10 in a plan view, and the height of the printed matter 10. And the range is determined (Act15). The control unit 7 may determine the height and range for scanning the surface preparation member 5 in the horizontal direction, or the user may operate the external information terminal 9.

In the case of latte art, the control unit 7 determines the height of the cup 11 and the height of the foaming milk 12 from the acquired information, and calculates at what level the unnecessary foaming milk 12 should be removed. Specifically, the control unit 7 determines that the circular portion detected at the same height is the cup 11, and sets the height as the height of the cup 11. Further, the control unit 7 sets the height of the region inside the circular portion as the height of the frothed milk 12. In order to secure a wide flat foam surface and print an image, the surface preparation member 5 is scanned at a height as close as possible to the height of the edge of the cup 11 to remove excess foaming milk 12 in the height direction. It is desirable to do. As a preferred example, as shown in FIG. 6 (c), the surface preparation member 5 is horizontally scanned at a height, for example, 2 mm higher than the height of the edge of the cup 11, and the frothed milk 12 above the height is scanned. Cut out and prepare the surface.

The scanning of the surface preparation member 5 is performed by moving the stage 31 in the Y direction (Act 16). The scanning start command may be automatically output by the control unit 7, or may be output by the user operating the operation unit 6 or the external information terminal 9. When the printed matter 10 is smaller than the length of the surface preparation member 5 in the X direction, the stage 31 is moved in the Y direction so that the center of the length of the surface preparation member 5 in the X direction passes on the center line of the printed matter 10. By making it, the surface is prepared in one scan. When the printed matter 10 is larger than the length of the surface preparation member 5 in the X direction, the surface is prepared by dividing the printed matter 10 in the X direction and scanning a plurality of times. FIG. 7 schematically shows how the spatula-shaped surface preparation member 5 pushes through the excess foaming milk 12 in the height direction to prepare the surface. When the spatula-shaped surface preparation member 5 is moved in the Y direction, the foamed milk 12 that has been pushed out is held on the upper surface 55 of the surface preparation member 5. That is, the surface preparation member 5 has a holding region for holding the foamed milk 12 that has been pushed out. Moreover, since the upper surface 55 is inclined so that the rear side is higher with respect to the moving direction, it is possible to prevent the foamed milk 12 that has been pushed out from dripping from the rear side.

When the surface preparation is completed, the control unit 7 determines the height and range for scanning the inkjet head 2 (Act 17). The height at which the inkjet head 2 is scanned is the height of the bubble surface prepared by the surface preparation member 5 in the previous step, plus the gap required for printing. The gap required for printing is, for example, 1 to 3 mm. When improving the image quality, the gap is set to 1 mm. The range for scanning the inkjet head 2 is determined based on the shape of the image to be printed and the installation position of the printed matter 10. Further, the size of the image is adjusted so that the image fits within the contour of the printed matter 10 in a plan view. Further, the image to be printed may be rotated so that the handle portion of the cup 11 that appears in the plan view in detecting the height of the printed matter 10 is located on the right side of the image, for example. That is, the image faces upward when the cup 11 is held with the right hand. The control unit 7 may determine the height and range of scanning the inkjet head 2, or the user may operate an external information terminal 9.

Subsequently, the control unit 7 moves the stage 31 so that the inkjet head 2 is located at the printing start position, and positions the inkjet head 2 at a height determined in the previous step. The scanning of the inkjet head 2 is performed by moving the stage 31 in the Y direction (Act 18). The scanning start command may be automatically output by the control unit 7, or may be output by the user operating the operation unit 6 or the external information terminal 9. When the printed matter 10 is smaller than the length of the inkjet head 2 in the X direction, the stage 31 is moved in the Y direction so that the center of the length of the inkjet head 2 in the X direction passes on the center line of the printed matter 10. Prints in one scan. As shown in FIG. 8, for example, when a small-sized inkjet head 2 is used, it is divided in the X direction and scanned a plurality of times for printing.

FIG. 9 schematically shows how the inkjet head 2 prints the pattern 101. Since the foaming surface of the foaming milk 12, which is the printing target surface, is adjusted in height and roughness to a certain level or less by the surface adjusting member 5 in the previous step, the gap between the inkjet head 2 and the foaming surface becomes uniform. ing. Therefore, the inkjet head 2 can be moved in the Y direction for printing, and it is possible to prevent the nozzle 28 from coming into contact with the bubble surface and causing ejection defects. Further, by printing with a uniform gap, it is possible to suppress the occurrence of image distortion. When printing is completed, the stage 31 and the inkjet head 2 are returned to the standby positions to complete the printing process (Act 19).

The foamed milk 12 which is a foamy substance does not become flat like printing paper even if the surface is prepared by the surface adjusting member 5. Therefore, as shown in FIG. 10, the inkjet head 2 may be scanned and printed while detecting the distance L to the bubble surface by the printed matter detection sensor 4. That is, the control unit 7 executes printing while moving the inkjet head 2 in the Z direction so that the gap, which is the distance L to the bubble surface detected by the printed matter detection sensor 4, is constant. Therefore, it is possible to print with a uniform gap, and it is possible to suppress the occurrence of image distortion. Scanning the inkjet head 2 while detecting the distance to the bubble surface in this way is effective when there is a possibility that bubbles may grow after the surface is prepared.

In the case of latte art, the height of the edge of the cup 11 and the foaming surface of the frothed milk 12 changes as the size of the cup 11 changes, ensuring that a constant amount of espresso and frothed milk 12 is always poured. There are many external factors such as the fact that the height of the foam of the frothed milk 12 may change depending on the temperature and humidity. Further, it is particularly difficult for a person to pour espresso and frothed milk 12 to keep the foaming surface height in the cup 11 constant. In response to such an external factor, according to the above-described embodiment, a spatula-shaped surface preparation member 5 is used to push through and remove excess foaming milk 12 in the height direction to obtain a flat surface to be printed. be able to. Since the cut foaming milk 12 is held on the upper surface 55 of the surface preparation member 5, it is possible to prevent it from dripping from the cup 11. Further, by aligning the printing target surface with the surface adjusting member 5, printing can be performed with a uniform gap, and it is possible to suppress the occurrence of image distortion.

Further, the printing application of the inkjet printer 2 is not limited to latte art. As shown in FIG. 11, the inkjet printer 2 can use the beer poured into the mug 102 as the printed matter 10. The control unit 7 scans the surface preparation member 5 at a height level close to the edge of the jug 102, and cuts off excess bubbles 103 in the height direction to prepare the surface.

Further, as shown in FIG. 12, the cream 104 applied to the surface of the cake can be used as the printed matter 10. The control unit 7 scans the surface preparation member 5 at, for example, the average height level of the cream 104, and cuts off the excess cream 104 in the height direction to prepare the surface. Instead of the cake, ice cream may be used as the printed matter 10.

Further, as shown in FIG. 13, the jelly 105 can be the printed matter 10. The control unit 7 scans the surface preparation member 5 at a height level at which a print target surface having an area where an image can be accommodated can be formed, and cuts off the upper portion of the jelly 105 to form a print target surface. For example, a vibration generator that slightly vibrates the surface preparation member 5 to the left and right may be provided to promote the action of pushing through the jelly 105, which is a semi-solid material.

Of course, FIGS. 11 to 13 are examples, and in addition to the beer foam 103, cream 104, and jelly 105, a three-dimensional soft material that can be pushed through by the surface preparation member 5 can be used as the printed matter 10. That is, the inkjet head 2 can use a foam such as foam, a highly viscous liquid such as cream, or a semi-solid material such as ice cream or jelly as the printed matter 10. Further, the printed matter 10 is not limited to food and drink as long as it is a three-dimensional soft material that can be pushed through by the surface preparation member 5.

As shown in FIG. 14A, the surface preparation member 5 may have a cross-sectional "dogleg" shape, for example, with the front side as a horizontal plane and the rear side as an inclined surface. Further, the plan view does not have to be rectangular, and as shown in FIG. 14B, for example, it may be U-shaped with the center recessed rearward.

Further, in the first embodiment, the inkjet head 2 and the surface preparation member 5 move in the Z direction, and the stage 31 moves in the X direction and the Y direction, but the configuration is not limited to this. For example, the stage 31 may be fixed, and the inkjet head 2 and the surface preparation member 5 may move in the XYZ directions, respectively. Alternatively, the inkjet head 2 and the surface preparation member 5 may be fixed, and the stage 31 on which the printed matter 10 is installed may be moved in the XYZ direction. That is, the inkjet head 2 and the surface preparation member 5 may be configured to be movable in the XYZ direction relative to the printed matter 10.

(Second Embodiment)
Subsequently, the inkjet printer 200 of the second embodiment will be described. The inkjet printer 200 of the second embodiment has the same configuration as the inkjet head 1 of the first embodiment, except that the configuration of the surface preparation member is different. Therefore, the same configuration as that of the inkjet head 1 of the first embodiment is designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 15 and 16, the surface preparation member 201 of the inkjet printer 200 of the second embodiment has a substantially rectangular outer shape, and is arranged so that the long side is along the X direction. As an example, the size of the surface preparation member 201 is a length of 100 to 120 mm in the X direction, a width of 60 to 70 mm in the Y direction, and a height of 20 to 30 mm in the Z direction. The surface preparation member 201 has a suction port 202 on the bottom surface. That is, the surface preparation member 201 has a hollow spatula shape. The suction port 202 is formed so as to extend in the X direction. The suction port 202 of the surface preparation member 201 communicates with one end of the suction path 203. The suction path 203 is, for example, a flexible tube made of a resin material. The suction device 204 is arranged, for example, on the upper surface of the main body 3. The other end of the suction path 203 is connected to the suction device 204. The material of the surface preparation member 201 is, for example, a resin material such as fluororesin or a metal material such as stainless steel.

As shown in FIG. 16, the suction device 204 includes a suction pump 205 such as a decompression pump. The suction pump 205 communicates with the suction path 203 via the trap device 206. The foaming milk 12 sucked from the suction port 202 of the surface preparation member 201 by driving the suction pump 205 is collected by the trap device 206. As shown in FIG. 17, the control unit 7 includes a suction circuit 207. The suction circuit 207 controls operations such as starting and stopping of the suction pump 205 at the time of surface preparation.

As shown in FIG. 16, the surface preparation member 201 is surface-adjusted by sucking the frothed milk 12 while pushing it all the way through. The height level at which the surface preparation member 201 is moved is determined in the same manner as in the first embodiment.

According to the above-described embodiment, a flat print object can be obtained by sucking the unnecessary foaming milk 12 while pushing it off with the surface preparation member 201 provided with the suction port 202. Since the foaming milk 12 is collected by the suction device 204, it is possible to prevent the foaming milk 12 from dripping from the cup 11 at the time of surface preparation. Further, by aligning the printing target surface with the surface adjusting member 201, printing can be performed with a uniform gap, and it is possible to suppress the occurrence of image distortion.

The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Inkjet printer 2 Inkjet head 3 Main body 4 Printed matter detection sensor 5 Surface preparation member 6 Operation unit 7 Control unit 201 Surface preparation member 202 Suction port 204 Suction device

Claims (5)

A spatula-shaped surface preparation member that pushes through a part of the three-dimensional printed matter,
An inkjet head that ejects ink onto the printable surface of the printed matter that has been smoothed by the surface preparation member being pushed through.
The printed matter detection sensor that detects the height of the printed matter and
An inkjet printer comprising: a control unit for determining a height at which the surface preparation member pushes through the printed matter based on a result detected by the printed matter detection sensor . A surface preparation member that sucks while pushing a part of the three-dimensional printed matter,
An inkjet printer comprising: an inkjet head for ejecting ink onto a print target surface of the printed matter whose surface is prepared by suction. The printed matter detection sensor that detects the height of the printed matter and
The inkjet printer according to claim 2 , further comprising a control unit for determining a height at which the surface preparation member pushes through the printed matter based on the result detected by the printed matter detection sensor. The inkjet printer according to claim 1, wherein the spatula-shaped surface preparation member has a holding region on the upper surface thereof for holding a part of the printed matter that has been pushed out. The inkjet printer according to any one of claims 1 to 4, wherein the inkjet head includes a cleaning member for cleaning the nozzle surface.

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