Inkjet printing device and curing method thereof

Abstract

The present invention discloses an inkjet printing device and a curing method thereof. The printing device includes a printing unit, a feeding unit, a curing unit and a control unit. The printing unit includes a printing carriage; the feeding unit is arranged below the printing unit, and is used to install the object to be printed and drive it to rotate; during the inkjet process, the curing range of the curing unit covers the image and text area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle, the curing unit moves synchronously with the printing carriage, and the control unit controls the reciprocating movement of the printing carriage along the first direction, the ink droplet spraying when each nozzle reaches the top of the area to be printed, the rotational movement of the object to be printed, and the curing operation of the curing unit. The printing carriage of the present invention completes all image and text printing after passing through the object to be printed once, the color ink droplets are cured in real time, and the transparent ink droplets are cured after leveling, so as to ensure the transparent effect, shorten the printing time, and improve the work efficiency.

Description

Technical Field

[0001] The present invention relates to an inkjet printing device using UV ink for printing and a curing method thereof, and in particular to an inkjet printing device in which the curing area of ​​the UV ink curing device covers the graphic area sprayed by other ink nozzles except for the transparent ink nozzle and a curing method thereof. Background Art

[0002] Inkjet printing devices are widely used in all walks of life. They mainly print the required images or text by ejecting ink drops from the nozzle and landing them on the corresponding positions of the printed media. Among the three commonly used inks - solvent ink, water-based ink and UV ink, UV ink has been widely used due to its fast curing speed, wide range of applicable media, and environmental protection. After printing with UV ink, a curing device is required to cooperate with it to cure the ejected images and texts. Due to the different structural designs of the printing devices, the installation method and installation position of the curing device are also different. One installation method is as follows: Figure 1 As shown, the curing devices 8a and 8b in the scanning inkjet printing device are generally arranged on both sides of the print nozzle 9. The print nozzle 9 is arranged along the length direction of the nozzle (printing paper feeding direction, i.e., Y direction), and each nozzle is arranged in parallel at a certain interval. The print nozzle 9 can be provided with color UV ink (cyan C, magenta M, yellow Y, black K). The setting direction of the curing devices 8a and 8b is parallel to the length direction of the nozzle (printing paper feeding direction, i.e., Y direction), and the curing range of the lamp beads along the Y direction covers the spraying range of one nozzle. Of course, the curing device can also choose to install only one 8a or 8b and set it on one side of the print nozzle 9. During the printing process, the printing medium is located below the nozzle and is fixed. The printing carriage 10 drives the print nozzle 9 and the curing devices 8a and 8b thereon to move back and forth along the X direction. During the reciprocating movement, the print nozzle 9 sprays ink droplets on the medium to be printed, and the ink droplets sprayed on the medium to be printed are cured by the curing devices 8a and 8b.

[0003] In addition, another installation method is to separate the curing device from the printing nozzle, such as Figure 2As shown, a print head (not shown in the figure) is installed under the printing carriage 2, and the printing carriage 2 can move back and forth along the beam 1. The object to be printed 7 (cylindrical rotatable object) is installed under the beam 1, and the curing device 6 is installed under the object to be printed 7. It is set as two independent modules with the printing carriage 2 and is independently controlled. The curing device 6 is fixed during the printing process, and the curing range of the curing device 6 is greater than or equal to the width of the required printed image on the object to be printed 7. During the printing process, the object to be printed 7 rotates around its own central axis, and the printing carriage 2 moves continuously along the beam 1. During the movement, the print head sprays ink droplets onto the rotating object to be printed 7 to form images, and at the same time, the UV lamp in the curing device 6 solidifies the ink on the object to be printed 7 in real time. The above description is for the case where only color ink is printed without transparent ink. If transparent ink needs to be printed after color graphics are printed, since transparent ink needs some time to flow after being sprayed onto the medium to be printed, it cannot be directly cured in real time using UV lamps, otherwise an uneven transparent surface will appear. Instead, the color ink needs to be printed first and the color ink needs to be cured synchronously, and then the UV lamp of the curing device 6 is turned off, and the printing carriage 2 moves back to the starting position along the beam 1 and then sprays the transparent ink alone. After the transparent ink droplets are printed and leveled, the UV lamp of the curing device 6 is turned on again to cure the transparent ink. In this way, the printing carriage 2 needs to go back and forth along the beam 1 at least twice to complete the printing process of the color and transparent ink of an object to be printed, which increases the printing time and reduces the printing efficiency. Therefore, it is necessary to design a new curing method that can make the transparent ink and the color ink sprayed simultaneously and complete the entire printing operation in the process of passing over the object to be printed, and does not affect the leveling and curing of the transparent ink, thereby improving the printing efficiency. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide an inkjet printing device and a curing method thereof, in which transparent ink can be deposited simultaneously with color ink in a process of passing over a to-be-printed object.

[0005] To achieve the above-mentioned purpose, the present invention provides an inkjet printing device, comprising a printing unit, a feeding unit, a curing unit and a control unit, wherein the printing unit comprises a printing carriage, the printing carriage can perform a reciprocating motion along a first direction, a nozzle is installed on the printing carriage, and the nozzle comprises a color ink nozzle and a transparent ink nozzle; the feeding unit is arranged below the printing unit, and is used to install an object to be printed and drive the object to be printed to perform a rotational motion around its own central axis; the curing unit is characterized in that the curing unit moves synchronously with the printing carriage, and the arrangement direction of the lamp beads of the curing unit is parallel to the arrangement direction of the nozzles in the length direction of the nozzle, when ink is applied, the curing range covers the image and text area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle, the control unit controls the reciprocating motion of the printing carriage, the ink droplet ejection when each nozzle reaches the top of the area to be printed, the rotational motion of the object to be printed and the curing operation of the curing unit, the printing carriage completes all image and text printing after passing through the object to be printed once, and the printing carriage completes the transparent ink curing after returning.

[0006] In the above-mentioned inkjet printing device, the curing range L of the lamp bead of the curing unit is: D≤L≤(D+d), where D represents the total width of ink droplets ejected by other ink nozzles except the transparent ink nozzle, and d represents the distance between the transparent ink nozzle and the adjacent ink nozzle.

[0007] In the above inkjet printing device, the nozzles on the printing carriage are arranged in series along the first direction with equal spacing from head to tail according to their own length direction, and the nozzle connection lines in the length direction of each nozzle are coaxial and parallel to the first direction.

[0008] In the above-mentioned inkjet printing device, three nozzles are arranged on the printing carriage in sequence: a first nozzle, a second nozzle and a third nozzle. The first nozzle has four rows of nozzles, all of which are used to connect white ink; the second nozzle has four rows of nozzles, and the four rows of nozzles are respectively connected to black ink, cyan ink, magenta ink and yellow ink; the third nozzle has four rows of nozzles, all of which are used to connect transparent ink.

[0009] In the above-mentioned inkjet printing device, four nozzles are arranged on the printing carriage in sequence: the fourth nozzle, the first nozzle, the second nozzle and the third nozzle, the fourth nozzle is connected to the pre-treated ink, the first nozzle is connected to the white ink, the second nozzle is connected to the color ink, and the third nozzle is connected to the transparent ink.

[0010] In the above-mentioned inkjet printing device, the object to be printed is a cylinder, the area to be printed is a cylindrical object or a cone, and the area to be printed is a cone-shaped object.

[0011] In the above inkjet printing device, the curing unit may be located above, below or to the side of the object to be printed.

[0012] The curing method using the above inkjet printing device is characterized by comprising the following steps:

[0013] (a) Place the object to be printed on the feeding unit;

[0014] (b) The printing carriage moves continuously from the initial position to the terminal position in a positive direction along a first direction, and the object to be printed rotates continuously around its own central axis. Each nozzle on the printing carriage sprays ink droplets to form images when passing over the area to be printed. While spraying ink, the curing unit moves synchronously with the nozzle and cures each layer of ink droplets except the transparent ink droplets;

[0015] (c) the printing carriage moves in the opposite direction from the end position to the initial position along the first direction, and the curing unit moves synchronously with the nozzle and cures the transparent ink droplets;

[0016] (d) determining whether there are still objects to be printed; if so, removing the printed object, installing the next object to be printed, and then repeating steps (b) to (d); if not, proceeding to step (e);

[0017] (e) Remove the printed object and printing is completed.

[0018] In the above curing method, the printing carriage in step (b) moves from the initial position to the final position once, and the color image and the transparent image layer are printed. In this process, the curing range of the curing unit covers the image area sprayed by the other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle.

[0019] In the above curing method, the curing range L of the lamp bead of the curing unit is: D≤L≤(D+d), where D represents the total width of ink droplets ejected by other ink nozzles except the transparent ink nozzle, and d represents the distance between the transparent ink nozzle and the adjacent ink nozzle.

[0020] Compared with the prior art, the present invention has the following beneficial effects: for the existing printing device for printing cylinders or cones, in the printing process of the continuous movement of the printing carriage, the transparent ink nozzle can follow the color ink nozzle in front to simultaneously discharge ink. Specifically, in the process of the printing carriage passing over the object to be printed, the other ink nozzles and the transparent ink nozzle all spray ink droplets to form a complete printed image and text. In this process, the curing device only solidifies the ink droplets sprayed by the other ink nozzles in real time, but does not solidify the transparent ink droplets in real time, so that the transparent ink droplets have leveling time before delayed curing, thereby ensuring the printing effect of the transparent ink, shortening the printing time for each object to be printed, and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a schematic diagram of the position of the curing device and the printing nozzle on the inkjet printing carriage in the prior art;

[0022] Figure 2 It is a schematic diagram of the structure of an inkjet printing device for printing curved surface objects such as cylinders or cones in the prior art;

[0023] Figure 3 A front view of the structure of an inkjet printing device in one embodiment of the present invention;

[0024] Figure 4 It is a schematic top view of the positions of a nozzle, a curing device and an object to be printed before printing in one embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the positions of each nozzle, the object to be printed and the curing device when the white ink nozzle enters the printing area after printing starts in another embodiment of the present invention;

[0026] Figure 6 A schematic diagram of the positions of the white ink jet head and the color ink jet head when the white ink jet head and the color ink jet head enter the printing area after printing starts, and the object to be printed and the curing device in another embodiment of the present invention;

[0027] Figure 7 A schematic diagram of the positions of the white ink nozzle, the color ink nozzle and the transparent ink nozzle when all of them enter the printing area during the printing process of another embodiment of the present invention, the objects to be printed and the curing device;

[0028] Figure 8 A schematic diagram of the positions of each inkjet head, the object to be printed and the curing device when the white inkjet head and the color inkjet head have left the printing area during the printing process in another embodiment of the present invention;

[0029] Fig. 9 A bottom view showing the positions of a curing device and each nozzle in another embodiment of the present invention;

[0030] Fig.10 A schematic diagram of the positions of each nozzle, the object to be printed and the curing device during the printing process in another embodiment of the present invention;

[0031] Fig.11 for Fig.10 Schematic diagram of the positions of the nozzles, the object to be printed and the curing device after the middle nozzle and the curing device move a certain distance along the A-axis direction;

[0032] Fig.12 A left view showing the positions of a nozzle, an object to be printed and a curing device in another embodiment of the present invention;

[0033] Fig.13A schematic diagram of the positions of each nozzle, the object to be printed and the curing device in an embodiment in which the object to be printed is a cone;

[0034] Fig.14 The figure is a printing flow chart in one embodiment of the present invention.

[0035] The numbers in the figure are respectively represented as follows: beam 1, printing carriage 2, mounting mechanism for the object to be printed 3, ink scraping and maintenance device 4, nozzle 5, curing device 6, curing device 6A, curing device 6B, curing device 6C, curing device 6D, curing device 6E, curing device 6F, lamp bead 61, object to be printed 7, cone object to be printed 8, curing devices 8a, 8b, printing nozzle 9, printing carriage 10, first nozzle 5a, second nozzle 5b, third nozzle 5c, fourth nozzle 5d, reciprocating motion direction X direction, printing paper feeding direction Y direction, first direction (A axis direction) direction), the second direction (B direction), the C direction, the D direction, the A' direction, the white background layer M, the color image layer N, the transparent ink layer P, the area R is the image area sprayed by the ink nozzles other than the transparent ink nozzle, the area S is the transparent ink area, the lamp bead curing range L, D represents the total width of the ink droplets sprayed by the ink nozzles other than the transparent ink nozzle, d represents the distance between the transparent ink nozzle and the adjacent ink nozzles, the irradiation area boundary u at the end of the curing device, the front end boundary v of the transparent ink droplets sprayed by the transparent ink nozzle, and the angle α between the curing device 6F and the horizontal direction. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Figure 3The inkjet printing device in one embodiment of the present invention is shown. The inkjet printing device includes a printing unit, a curing unit, a feeding unit and a control unit. The printing unit includes a printing carriage 2. A nozzle 5 is installed on the printing carriage 2. UV ink is sprayed onto the object to be printed through the nozzle 5 to form a preset image or text. The printing carriage 2 can perform a reciprocating motion in the first direction (axis A direction) along the crossbeam 1. The curing unit includes a curing device (blocked by the nozzle 5 in the figure). The curing device is arranged on the printing carriage 2. The irradiation range of the lamp beads in the curing device only covers the spraying area of ​​the white ink nozzle and the color ink nozzle, and cannot irradiate the transparent ink droplet area sprayed by the transparent ink nozzle. The curing device moves with the printing carriage 2, that is, it moves synchronously with the nozzle 5. The feeding unit includes a mounting mechanism 3 for the object to be printed. The object 7 to be printed is placed on the mounting mechanism 3 for the object to be printed and is located below the crossbeam 1. Driven by a driving motor (not shown in the figure), the object 7 to be printed can perform a rotational motion with the second direction (direction B), that is, the rotation center line of itself, as the central axis. The control unit is used to control the reciprocating motion of the printing carriage 2 along the first direction (A axis direction), the ink droplet ejection of the nozzle 5, the rotation motion of the object to be printed 7 in the second direction (B direction) with its own central axis as the rotation center, and the curing operation of the curing device on the ink. During the printing process, the control unit controls the printing carriage 2 to continuously move in the positive direction (A arrow direction) of the first direction, the object to be printed mounting mechanism 3 drives the object to be printed 7 to rotate at a uniform speed in the second direction (B direction), and controls all the nozzles 5 on the printing carriage 2 to eject ink droplets to the image and text area to be printed when passing over the object to be printed 7 once, and controls the curing device to cure other ink droplets except transparent ink droplets ejected by the nozzle 5. The object to be printed 7 of the present invention can be a cylindrical object or an object with a cylindrical part to be printed, or a conical object or an object with a conical part to be printed. In addition, an ink scraping maintenance device 4 can be provided below the initial position of the printing carriage 2 and on one side of the beam 1 (the right side when facing the printing device), and the ink scraping maintenance device 4 is used to scrape ink or perform maintenance on the nozzle 5.

[0038] According to the following Figure 4The schematic top view of the positions of the nozzles, curing device and the object to be printed before printing is further explained. In this embodiment, three printing nozzles are arranged on the printing carriage: the first nozzle 5a, the second nozzle 5b and the third nozzle 5c. The three printing nozzles are arranged in series along the A axis direction with equal spacing from head to tail in the nozzle length direction. The nozzle connection lines in the length direction of each nozzle are coaxial and parallel to the A axis direction. Among them, the first nozzle 5a has four rows of nozzles, all of which are used to connect white ink (W); the second nozzle 5b has four rows of nozzles, and the four rows of nozzles are respectively connected to black ink (K), cyan ink (C), magenta ink (M) and yellow ink (Y); the third nozzle 5c has four rows of nozzles, all of which are used to connect transparent ink (V). When a certain ink is not needed to spray images and texts, the nozzle does not need to be connected to the ink. In actual situations, the printing nozzles can be increased or decreased as needed, or a printing nozzle with two rows of nozzles can be used. The selection and connection method of different inks can also be changed according to actual needs, and are not limited to the description in the above embodiment. A curing device 6A is also designed on the printing carriage, on one side of the nozzle area in the figure, and the lamp beads on the curing device 6A are arranged along the A-axis direction, that is, the arrangement direction of the lamp beads on the curing device 6A is parallel to the arrangement direction of the nozzles on the length of the nozzle. The curing device 6A moves with the printing carriage, and the irradiation area of ​​the lamp beads 61 of the curing device 6A covers the image and text area where the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) spray ink, but cannot irradiate the area where the third nozzle 5c (transparent ink nozzle) sprays ink.

[0039] Next, according to Figure 5-8 The position diagram shown is used to specifically illustrate the control process of the nozzle, the object to be printed and the curing device during the printing process of one embodiment of the present invention. Before inkjet printing, the object to be printed 7 is placed on the object to be printed mounting mechanism. The placed object to be printed 7 moves vertically upward along the lifting mechanism below the object to be printed mounting mechanism, and reaches an optimum distance (generally between 1mm and 3mm) from the plane where the nozzle orifice at the lower end of the printing carriage 2 is located. Before printing starts, the printing carriage 2 is located at the initial position on one side of the first axis direction (axis A direction), and each nozzle has not entered the printing area and does not spray ink droplets, and the lamp beads of the curing device 6A are not lit. After clicking the start button, the control system controls the printing carriage 2 to move continuously in the positive direction of the first direction (direction of arrow A), and the object to be printed mounting mechanism drives the object to be printed 7 to rotate continuously in the second direction (direction B) around its own central axis, controls the nozzle on the printing carriage 2 to spray ink droplets, and controls the lamp beads on the curing device 6A to irradiate the ink droplets. As shown Figure 5As shown, after the inkjet printing starts, as the printing carriage 2 moves, the first nozzle 5a (white ink nozzle) first enters the area to be printed, and the control system controls the nozzle of the first nozzle 5a (white ink nozzle) to spray white ink droplets on the continuously rotating object to be printed 7, forming a white background layer M. At this time, the curing device 6A moving with the printing carriage 2 is in a lit working state, and the second nozzle 5b (color ink nozzle) and the third nozzle 5c (transparent ink nozzle) that have not entered the area to be printed do not spray ink temporarily. As the printing nozzle continuously moves in the positive direction (direction of arrow A) of the first direction, the second nozzle 5b (color ink nozzle) enters the area to be printed, and the control system controls the nozzles of the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) to jointly spray ink droplets on the continuously rotating object to be printed 7, and the color ink sprayed by the second nozzle 5b (color ink nozzle) covers the white background layer M sprayed by the first nozzle 5a (white ink nozzle), forming as shown in the figure. Figure 6 As shown in the color image layer N, the curing device 6A moving with the printing carriage 2 is always in the working state of lighting, and the third nozzle 5c (transparent ink nozzle) that has not entered the area to be printed does not spray ink temporarily. As the printing nozzle continues to move continuously in the positive direction of the first direction (the direction of the arrow A), the third nozzle 5c (transparent ink nozzle) also enters the area to be printed, and the control system controls the nozzles of the first nozzle 5a (white ink nozzle), the second nozzle 5b (color ink nozzle) and the third nozzle 5c (transparent ink nozzle) to jointly spray ink droplets on the continuously rotating object to be printed 7, and the transparent ink sprayed by the third nozzle 5c (transparent ink nozzle) covers the white background layer M sprayed by the first nozzle 5a (white ink nozzle) and the color image layer N sprayed by the second nozzle 5b (color ink nozzle), forming the following figure: Figure 7 The transparent image layer P shown in the figure, the curing device 6A moving with the printing carriage 2 is always in the working state of lighting. As the print heads continue to move in the positive direction of the first direction (the direction of the arrow A), each print head stops spraying ink after passing above the area to be printed, as shown in FIG. Figure 8As shown, the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) leave the printing area, and the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) no longer spray ink droplets, and the third nozzle 5c (transparent ink nozzle) is still above the area to be printed and sprays transparent ink droplets to form a transparent layer P. Finally, after the third nozzle 5c (transparent ink nozzle) also leaves the area to be printed, the printing image is completely completed. At this time, the printing carriage 2 is at the end position of the first axis direction (axis A direction), and then the printing carriage 2 returns to the initial position in the opposite direction of the first direction (the opposite direction of the arrow A). During the return of the printing carriage 2, the curing device 6A is in a lighted working state to cure the transparent ink droplets. This process has achieved leveling of the transparent ink (the leveling time takes about 1 second), so the curing quality of the transparent image layer P can be ensured. After the curing is completed, the operator removes the printed object 7 and places the next object to be printed to print the next object to be printed.

[0040] like Fig. 9The figure shows a schematic diagram of the upward position of the curing device and the nozzle in another embodiment of the present invention. In this embodiment, four printing nozzles are arranged on the printing carriage 2, from left to right (the nozzle that first enters the image and text area to be printed is on the left): the fourth nozzle 5d, the first nozzle 5a, the second nozzle 5b and the third nozzle 5c. The four printing nozzles are arranged in series along the A-axis direction in the nozzle length direction with equal spacing from head to tail. The nozzle connection lines in the length direction of each nozzle are coaxial and parallel to the A-axis direction. Among them, the fourth nozzle 5d has four rows of nozzles for connecting pretreatment ink (P); the first nozzle 5a has four rows of nozzles, all of which are used to connect white ink (W); the second nozzle 5b has four rows of nozzles, and the four rows of nozzles are respectively connected to black ink (K), cyan ink (C), magenta ink (M), and yellow ink (Y); the third nozzle 5c has four rows of nozzles for connecting transparent ink (V). A curing device 6B is also designed on the printing carriage, on one side of the nozzle area in the figure, and the lamp beads on the curing device 6B are arranged along the A-axis direction, that is, the arrangement direction of the lamp beads on the curing device 6B is parallel to the arrangement direction of the nozzles on the length of the nozzle. The curing device 6B moves with the printing carriage, and the irradiation area of ​​the lamp beads 61 of the curing device 6B covers the image and text area where the fourth nozzle 5d (pretreatment ink nozzle), the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) spray ink, but cannot irradiate the transparent ink area sprayed by the third nozzle 5c (transparent ink nozzle). The printing principle in the working state is the same as the above-mentioned printing method: during the continuous movement of the printing carriage 2 from the initial position to the terminal position along the positive direction of the first direction (the direction of the arrow A), each nozzle sprays ink droplets when passing through the image and text area to be printed, and the curing device 6B remains in a constant light state to cure the pre-treated ink droplets, white ink droplets and color ink droplets sprayed onto the surface of the object to be printed, but the curing range cannot irradiate the transparent ink droplet area, so the transparent ink droplets are given leveling time. When the printing is completed, the printing carriage 2 returns from the terminal position along the reverse direction of the first direction (the opposite direction of the arrow A) to the initial position, and the curing device 6B continues to be in a lighted working state to cure the transparent ink droplets after leveling. After the printing carriage 2 returns to the initial position, the object to be printed has completed the printing and curing operations of the pre-treated coating, white background layer, color pattern layer and transparent ink layer, and the next object to be printed is replaced and the above operations are repeated.

[0041] In addition to the example in which the curing device is installed on the printing carriage as described above, it can also be arranged below the object to be printed 7, such as Figure 10-11 The curing device 6C is in the position shown, and the lamp beads of the curing device 6C are irradiated upward. The fourth nozzle 5d, the first nozzle 5a, the second nozzle 5b and the third nozzle 5c on the printing carriage 2 are the same as those mentioned above. Fig. 9The curing range of the curing device 6C covers the printing image area R of the fourth nozzle 5d (pretreatment ink nozzle), the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle). The area R can be defined as the image area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area S sprayed by the third nozzle 5c (transparent ink nozzle). During the continuous movement of the printing carriage 2 from the initial position to the terminal position along the positive direction of the first direction (the direction of the arrow A), the curing device 6C moves back and forth synchronously with the nozzles on the printing carriage 2. The movement direction of the curing device 6C is along the C direction shown in the figure, and the C direction is parallel to the A direction. During the movement of the curing device 6C from the initial position to the terminal position along the C direction, the curing range is always the area R. The principle of the printing process is the same as above. Figure 5-8 The principle is the same. The curing range L of the lamp beads of the curing device during the printing process can be defined as follows: D≤L≤(D+d), where D represents the total width of the ink droplets ejected by the other ink nozzles except the transparent ink nozzle, and d represents the distance between the transparent ink nozzle and the adjacent ink nozzles, so as to meet the requirement that the irradiation area boundary u at the end of the curing device is located in front of the front boundary v of the transparent ink droplets ejected by the transparent ink nozzle (the direction of the arrow C is defined as the front). After the printing is completed, during the return of the printing carriage, the curing device 6C is still in the lighting state, and continues to cure the transparent ink droplets after leveling above while following the synchronous movement of the nozzles on the printing carriage 2. When the printing carriage returns to the initial position, the transparent ink is also cured. The operator removes the printed and cured object 7 and places the next object to be printed to carry out the operation of the next object to be printed.

[0042] In addition to the above-mentioned installation positions, the curing device can also be arranged on the horizontal side of the object to be printed 7, such as Fig.12 When set in this position, the curing range of the curing device also covers the image and text area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle. During the continuous movement of the printing carriage 2 from the initial position to the terminal position along the positive direction of the first direction (the direction of the arrow A), the curing device also moves back and forth synchronously with the nozzles on the printing carriage 2. The printing process and principle are the same as those described above. Figure 10-11 The same as the embodiment.

[0043] The objects to be printed in the above embodiments are all cylinders. When the object to be printed is a cone, the method of the present invention is also applicable. Fig.13 As shown, the nozzle arrangement on the printing carriage 2 is Figure 4The arrangement described in the embodiment is the same, and a total of three print heads are set: the first nozzle 5a, the second nozzle 5b and the third nozzle 5c. The nozzle length direction of the three print heads is arranged in series with equal spacing along the A-axis direction, and the nozzle connection lines in the length direction of each nozzle are coaxial and parallel to the A-axis direction. Among them, the first nozzle 5a has four rows of nozzles, all of which are used to connect white ink (W); the second nozzle 5b has four rows of nozzles, and the four rows of nozzles are respectively connected to black ink (K), cyan ink (C), magenta ink (M) and yellow ink (Y); the third nozzle 5c has four rows of nozzles, all of which are used to connect transparent ink (V). After the cone-shaped object to be printed 8 set below the printing carriage 2 is adjusted by the parallel adjustment mechanism in the installation mechanism, the upper surface of the cone-shaped object to be printed 8 is parallel to the A-axis direction, and the distance between each point on the upper surface and the plane where the nozzle orifice of the nozzle at the lower end of the printing carriage 2 is located is the optimal distance (generally between 1mm and 3mm). A curing device 6F is arranged below the conical object to be printed 8. The upper surface of the lamp bead of the curing device 6F is adjusted to be parallel to the lower surface of the conical object to be printed 8, that is, parallel to the A' direction in the figure, and has an angle α with the horizontal direction. The lamp bead of the curing device 6F irradiates upward. The curing range of the curing device 6F covers the printing image and text areas of the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle), but cannot irradiate the transparent ink area sprayed by the third nozzle 5c (transparent ink nozzle). During the continuous movement of the printing carriage 2 from the initial position to the end position along the positive direction of the first direction (the direction of the arrow A), the curing device 6 F moves back and forth synchronously with each nozzle on the printing carriage 2, and the movement direction of the curing device 6F is along the A' direction shown in the figure, and the angle between the A' direction and the A direction is α. When printing ink, the curing device 6F always cures the image and text area of ​​the first nozzle 5a (white ink nozzle) and the second nozzle 5b (color ink nozzle) in the process of moving from the initial position to the final position along the A' direction. In the continuous movement process of the printing carriage 2 from the initial position to the final position along the positive direction of the first direction (the direction of the arrow A), the cone object to be printed 8 rotates along its own rotation center axis in the D direction. The principle of the printing inkjet process is the same as the above Figure 5-8 The principle is the same as described above. After the printing is completed, during the return of the printing carriage, the curing device 6F is still in the lighted state, and continues to cure the transparent ink droplets after leveling above while following the synchronous movement of the nozzles on the printing carriage 2. When the curing is completed, the operator removes the printed cone object 8 and places the next object to be printed to carry out the operation of the next object to be printed.

[0044] According to the following Fig.14The printing process in one embodiment of the present invention is specifically described. The printing steps are as follows: Step 1 S1: first install the object to be printed on the feeding unit. If it is a cylinder or an object with a cylindrical printing area, adjust the upper surface to the plane where the nozzle orifice is located to be the optimal printing distance. If it is a cone or an object with a cone printing area, adjust the upper surface to be parallel to the plane where the nozzle orifice is located and the distance between the two is the optimal printing distance; Step 2 S2: The printing carriage moves continuously from the initial position to the terminal position in the first direction, and the object to be printed under the printing carriage rotates continuously around its own central axis. Each nozzle on the printing carriage sprays ink droplets to form images when passing over the area to be printed. While spraying ink, the curing device moves synchronously with the nozzle and solidifies each layer of ink droplets except the transparent ink droplets. After one pass, the color graphics and transparent ink droplets are printed. It should be noted that the curing range of the curing device covers the graphics area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle; in the third step S3, the printing carriage moves from the end position to the initial position in the opposite direction of the first direction, and each nozzle no longer sprays ink. The curing device moves synchronously with the nozzle and solidifies the transparent ink droplets; in the fourth step S4, it is determined whether there is still an object to be printed; if so, the fifth step S5 is performed to remove the printed object, install the next object to be printed, and then repeat steps S2-S4. If not, the sixth step S6 is performed to remove the printed object and the printing is completed.

[0045] The above embodiments are all implementation methods in which the printing carriage moves and the object to be printed rotates at the original position. In addition to this relative motion form, the printing carriage can also be set to be stationary and the object to be printed can be rotated while moving relative to the printing carriage. The curing device is still set on one side of the print head of the printing carriage and covers the image and text area sprayed by other ink nozzles except the transparent ink nozzle, as shown in the attached figure. Figure 5-8 In the embodiment of the present invention, the printing carriage 2 is replaced to be fixed, and the object to be printed 7 continuously moves relative to the printing carriage 2 in the opposite direction of the first direction (opposite direction of arrow A), and the ink application and curing principles are the same as the above case; when the printing carriage is set to be stationary, and the object to be printed is rotated while moving relative to the printing carriage, the curing device can also be set to be separated from the printing carriage, and the curing device still only covers the image and text area sprayed by the ink nozzles other than the transparent ink nozzle during the ink application process. In this case, the object to be printed and the curing device need to move synchronously, and during the ink application process, the curing device only cures the image and text area sprayed by the ink nozzles other than the transparent ink nozzle. After the ink application is completed, the curing device cures the transparent ink separately, and the printing principle and control method are the same as the above method.

[0046] It should be pointed out that any modifications made according to the specific embodiments of the present invention do not depart from the spirit of the present invention and the scope of the claims.

Claims

1. An inkjet printing device, comprising a printing unit, a feeding unit, a curing unit and a control unit, wherein the printing unit comprises a printing carriage, the printing carriage can perform a reciprocating motion along a first direction, a nozzle is installed on the printing carriage, the nozzle comprises a color ink nozzle and a transparent ink nozzle, the nozzles are arranged in series along the first direction at equal intervals in their own length direction, the nozzle lines in the length direction of each nozzle are coaxial and parallel to the first direction; the feeding unit is arranged below the printing unit, and is used to install an object to be printed and drive the object to be printed to rotate around its own central axis; characterized in that The curing unit moves synchronously with the printing carriage, and the arrangement direction of the lamp beads of the curing unit is parallel to the arrangement direction of the nozzles on the length of the nozzle. When the ink is applied, the curing range covers the image and text area sprayed by other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle. The curing range L of the lamp beads of the curing unit is: D≤L≤(D+d), where D represents the total width of the ink droplets sprayed by other ink nozzles except the transparent ink nozzle, and d represents the distance between the transparent ink nozzle and the adjacent ink nozzles. The control unit controls the reciprocating movement of the printing carriage, the ink droplet spraying when each nozzle reaches the top of the to-be-printed area, the rotational movement of the object to be printed, and the curing operation of the curing unit. The printing carriage completes all image and text printing after passing through the object to be printed once, and the printing carriage completes the transparent ink curing after returning.

2. The inkjet printing device according to claim 1, wherein: Three nozzles are arranged on the printing carriage in sequence: a first nozzle, a second nozzle and a third nozzle. The first nozzle has four rows of nozzles, all of which are used to connect white ink; the second nozzle has four rows of nozzles, and the four rows of nozzles are respectively connected to black ink, cyan ink, magenta ink and yellow ink; the third nozzle has four rows of nozzles, all of which are used to connect transparent ink.

3. The inkjet printing device according to claim 1, wherein: Four nozzles are arranged on the printing carriage in sequence: a fourth nozzle, a first nozzle, a second nozzle and a third nozzle, the fourth nozzle is connected to pre-treatment ink, the first nozzle is connected to white ink, the second nozzle is connected to color ink, and the third nozzle is connected to transparent ink.

4. The inkjet printing device according to claim 1, wherein: The object to be printed is a cylinder or a cone.

5. The inkjet printing device according to claim 1, wherein: The area to be printed is cylindrical or conical.

6. The inkjet printing device according to claim 1, wherein: The curing unit may be located above, below or to the side of the object to be printed.

7. The curing method of the inkjet printing device according to claim 1, characterized in that: The steps include: (a) Place the object to be printed on the feeding unit; (b) The printing carriage moves continuously from the initial position to the terminal position in a positive direction along a first direction, and the object to be printed rotates continuously around its own central axis. Each nozzle on the printing carriage sprays ink droplets to form images when passing over the area to be printed. While spraying ink, the curing unit moves synchronously with the nozzle and cures each layer of ink droplets except the transparent ink droplets; (c) the printing carriage moves in the opposite direction from the end position to the initial position along the first direction, and the curing unit moves synchronously with the nozzle and cures the transparent ink droplets; (d) determining whether there are still objects to be printed; If yes, remove the printed object, install the next object to be printed, and then repeat steps (b)-(d); if no, proceed to step (e); (e) Remove the printed object and printing is completed.

8. The curing method according to claim 7, characterized in that: In step (b), the printing carriage moves from the initial position to the final position once, and the color graphics and transparent ink droplets are printed. In this process, the curing range of the curing unit covers the graphics area sprayed by the other ink nozzles except the transparent ink nozzle, but cannot irradiate the transparent ink area sprayed by the transparent ink nozzle.

Images