JPH0499688A - Ink jet printer - Google Patents

Abstract

PURPOSE:To obtain an ink jet printer which can print a copy image uniformly by arranging a plurality of nozzle heads, having a plurality of ink jet nozzle holes arranged in same pitch, two-dimensionally so that the rows of the ink jet nozzle holes fully cover a sheet material laterally while shifting in the longitudinal direction of the sheet material being carried. CONSTITUTION:Image data of an original image are converted into print data for each nozzle hole of four colors and stored, in time series, in a memory corresponding to the nozzle hole. When all data are stored, a servo motor 7 drives a drum 5 to carry a sheet material 3 to a printing position. Ink dots are then jetted to a predetermined position on the sheet material 3, according to the carrying timing thereof and based on the print data, thus printing out a copy image. According to the constitution, the ink dots are jetted with same pitch over the entire width of the sheet material without scanning a nozzle head and a copy image can be printed out uniformly without causing joint or pattern.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is capable of spraying ink from a nozzle onto a Q sheet-like object such as fabric, paper, plastic, or metal plate to create an arbitrary color pattern consisting of a collection of ink dots. The present invention relates to an inkjet printing device for printing.

[Prior Art] Conventionally, screen printing machines and printing machines have been widely used to print designs on fabrics, etc., but in addition to these, printers employing the so-called inkjet method have also been used. For example, in the cylindrical scanning printer shown in FIG.
The main scanning is performed by rotating the drum 33 by a servo motor 35, and the sub-scanning is performed by horizontally moving the carriage 31 by a step motor 36. Ink dots are sequentially sprayed onto the sheet-like material 37 to form a color image. The ink head 32 is controlled by a feedback signal from an encoder 38 so that ink is ejected to the same position.

FIG. 8 shows an example of the configuration of a continuous printing device, in which the feeding direction of the sheet-like material 37 that is continuously fed by the drum 33 is the sub-scanning direction, and the inkjet head 40 is moved in the horizontal direction, which is the main scanning direction. form an image.

[Problems to be Solved by the Invention] In the conventional screen printing method described above, a tracing screen is created on the original design, and a photosensitive liquid is applied to the gauze stretched over the formwork for each dye color to be used. It requires complicated processes such as creating a pattern and screen printing, which takes time and! The problem was that it was expensive.

Furthermore, in conventional inkjet printing devices, as mentioned above, several inkjet nozzles scan cloth etc. in the main scanning direction or the sub-scanning direction, but the response speed of the inkjet nozzles is This has the problem that the processing speed of the device is limited by the nozzle response speed, and high-speed processing cannot be achieved because printing is performed using a small number of nozzles. Furthermore, since the inkjet nozzle is scanned, there is a problem in that striped patterns tend to appear on the print.

To solve this problem, it is possible to arrange the nozzle so that it covers the entire width of the fabric to be printed, but
For example, regarding statically controlled inkjet nozzles,
It is difficult to make the air flow and ink meniscus uniform for thousands to tens of thousands of nozzles in terms of workmanship and accuracy. In addition, when a nozzle head is configured with a constant number of nozzles, for example, 24 nozzles are arranged in a horizontal row, dummy air discharge ports are provided outside the 1st and 24th nozzles, and the end of the frame is It is not configured to be used for ink ejection. Therefore, these nozzle heads cannot be arranged horizontally in a row to cover the width of the cloth.

Furthermore, if the scanning is divided into areas to increase the processing speed, the problem arises that the printed image has rough seams, and the number of movable parts increases, which is undesirable from a structural standpoint.

As described above, all of the above-described conventional printing apparatuses have the problem that the processing speed cannot be increased and that striped patterns are produced by scanning.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet printing device that can perform high-speed printing and print evenly.

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following configuration.

That is, the inkjet printing device according to the present invention sprays printing liquids of multiple colors from inkjet nozzles onto a sheet-like object such as a cloth that is conveyed in a horizontal direction, based on image data obtained by color-separating an original image. In an inkjet printing device that prints a duplicate image with a desired color pattern, a plurality of inkjet heads each having a plurality of inkjet nozzle holes arranged in a row at an equal pitch are shifted back and forth with respect to the running direction of a sheet-like object being transported. and the nozzle holes of the plurality of inkjet heads are arranged two-dimensionally so as to cover at least the entire width of the sheet-like object.
In the invention of.

The present invention is characterized in that print data obtained based on image data is obtained as print data for each nozzle hole, and a memory is provided for storing the print data in one-to-one correspondence with the nozzle holes. (Second invention).

[Function] A plurality of nozzle heads each having a plurality of inksheet nozzle holes arranged in a row at an equal pitch are shifted in the front and back direction of the sheet-like object being conveyed, and the rows of these inksheet nozzle holes are arranged at least in the sheet-like shape. Since the nozzle heads are arranged two-dimensionally to cover the entire width of the object, by driving each nozzle head in chronological order while conveying the sheet-like object, the nozzle heads can be arranged in rows across the entire width of the sheet-like object. Ink dots can be sprayed in the same manner as when the nozzle holes are arranged at equal pitches, and reproduced images can be printed evenly.

In addition, a memory is provided for each nozzle hole, in which print data based on image data obtained by color separation of the original image is stored in chronological order, and after all data is stored, printing is performed based on the print data. For example, the time required for reading and distributing data can be shortened, and since nozzle head scanning time is not required, high-speed printing can be performed.

[Embodiment] FIG. 1 is a perspective view showing the configuration of an inkjet printing apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the circuit configuration thereof. The inkjet printing device 1 is a device that places a sheet-like object 3 to be printed on an endless belt 2 and sequentially conveys it to a printing position by driving a drum 5 to print on the sheet-like object 3,
The drum 5 is driven by a surf motor 7.

The inkjet nozzle that sprays ink dots onto the sheet material 3 uses a plurality of inkjet nozzle heads each having 24 nozzle holes arranged in rows, which are shifted back and forth so as to cover the entire width of the sheet material being conveyed. It is configured as a rad array 8 with nozzles arranged dimensionally. Details of the arrangement will be described later.

Each nozzle of the inkjet nozzle head (hereinafter referred to as nozzle head) uses an electrostatic force to draw out the ink supplied from the ink tank 9 into the nozzle from the ink interface of the minute nozzle hole using an electrostatic control method, and further draws air from the air supply device 10. It is composed of a known mechanism that creates an inkjet stream by pulling out the inkjet stream in the form of a thread.

The control device 11 controls the nozzle drive timing, such as applying a signal voltage to the electrodes of the nozzle head.

As shown in FIG. 2, the control device 11 first sends print data based on image data obtained by color-separating a color original image to a data distribution CPU 14 via an input means 13. The data distribution CPU 14 transfers the print data to the nozzles for each nozzle head 20 of the RAD array 8, and stores the data in a data ROM 15 for correcting the nozzle characteristics of each nozzle head.
This data is stored in the memory 17 corresponding to the 24 nozzle holes on a one-to-one basis. After the print data is stored in the memory, the nozzle drive voltage generator 18 is activated based on each data.
A signal voltage is applied to the nozzle, and desired ink dots are sprayed onto the sheet-like object, forming a duplicate image based on the color original image.

However, the image is formed not by scanning the nozzle head as in the past, but by forming an array in which the required number of nozzle heads with multiple nozzle holes are arranged in a two-dimensional manner. This is done in a stationary state based on print data sent in chronological order.

As shown in FIG. 3, the nozzle head 2o has a nozzle at the end of each nozzle head at a pitch of 24 nozzle holes arranged in one head with respect to the traveling direction in which the sheet-like material 3 is conveyed. The 13 nozzles from No. I to No. 13 are arranged two-dimensionally while being separated horizontally by a distance corresponding to the distance, and are shifted back and forth. The arrangement is such that the distance from the hole to the right end nozzle hole of the No. 13 nozzle head at the other end covers the entire width of the sheet-like material. Moreover, in the illustrated example, numbers from No. +4 to No. 26 are arranged in exactly the same way as above.
The following 13 nozzle head groups are arranged following the above head group and moved in parallel by a distance that is half the nozzle hole pitch.

By arranging the nozzle heads in this way, for example, the pitch of the 24 nozzle holes arranged in one head can be set to 0.
If it is 5mm, nozzle head No. 1 to No. +3
Up to 312 nozzle holes (13 heads x 24 nozzles)
covers the entire width of the sheet-like object, and is equivalent to being arranged in a horizontal row at a pitch of 0.5 degrees as shown in FIG. However, the nozzle head groups from No. 4 to No. 26 have a pitch of 0.251101, which is half the nozzle pitch, compared to the nozzle head groups from No. ] to No. 13.
In the state of parallel movement, 312 nozzles are arranged in a horizontal line at a pitch of 0.5 mm, as shown above, and if you look at all the nozzle holes in the upper and lower nozzle head groups, as shown in Figure 5. They are arranged at a pitch of 0.25m+o. As shown in Figure 4, the total width of the nozzle hole is 155.75 ((13 heads x 12 mm-0
, 5) +0.25), and the total width of the sheet-like object is 150
It can cover objects up to mm.

The multi-nozzle head groups of upper and lower two blocks each consisting of 13 nozzle heads are arranged for ejecting yellow (Y) ink, and the nozzle head array 8 further includes magenta (M) and cyan (C). , black (B) ink ejecting nozzle heads are arranged sequentially for each color in the same way as described above. Therefore, Y, M, C, B4
For each color, the number of nozzle heads is 26 (+3 heads x 2 blocks), the number of nozzle holes is 624 (26 heads x 24 nozzle holes), the nozzle pitch is 0.25 mm, and the total nozzle width is 155.7 mm.
The nozzle head is 5 Inm thick, or the colors Y, M, C, and B are arranged in the order of blocks to form a rad array to the nozzle.

As described above, each nozzle head of the nozzle rad array 8 configured in this manner is provided with a memory 17 that corresponds one-to-one to the nozzle hole of each head, and print data is stored in this memory. This memory uses a high-speed line memory in which write and read operations can be performed independently and asynchronously in different cycles.

In order to print using the inkjet printing device configured as described above, first, the image data obtained by color separation of the original image is converted into print data for each nozzle hole for each of the four colors, and the print data is Data is stored in memory 17 corresponding to the nozzle hole in chronological order. After all the data has been stored in the memory, the drum 5 is moved by the surf motor 7.
is driven to transport the sheet-like material 3 to the printing position.

Predetermined ink dots are sprayed from each nozzle hole at a predetermined position on the sheet-like material 3 based on print data in accordance with the transport timing of the sheet-like material 3 that is intermittently transported, and a duplicate image is printed.

In this way, according to the apparatus of the above embodiment, ink dots can be sprayed at equal pitches over the entire width of the sheet-like object to be printed without scanning the nozzle head, and the reproduced image can be made seamlessly and without striped patterns. It is possible to print evenly without any problems. Moreover, it eliminates the round trip time required for scanning, and unlike conventional methods, it is not necessary to temporarily store print data for one or several scans in a buffer memory and read and distribute the data for each nozzle hole, allowing for high-speed printing. It becomes possible.

Therefore, compared to the textile printing method, the total time required from the original design to product shipment can be significantly shortened, including the fact that there is no need to create a printing plate. Furthermore, since the number of moving parts for scanning can be reduced, failures are less likely to occur, and the host computer can be quickly released and used for other processing, allowing the system to operate more efficiently.

In the above embodiment, the nozzle heads are arranged so that the pitch of the nozzle holes is halved as a whole, or they are arranged in a concentrated manner as shown in FIG. 6, and the nozzle heads are arranged so that the pitch of the nozzle holes becomes finer. It can also happen.

In this example, a static control type nozzle head is used, but the nozzle head is not limited to this, and other on-demand type nozzle heads may be used.

[Effects of the Invention] As is clear from the above description, according to the inkjet printing apparatus according to the present invention, it is possible to print a duplicate image based on an original image on a sheet-like object evenly and at high speed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, and FIG.
The figure is a block diagram showing the circuit configuration, Figure 3 is a diagram showing an example of nozzle head arrangement, Figure 4 is a diagram conceptually explaining an example of nozzle head arrangement, and Figure 5 is the configuration of the pitch of nozzle holes. FIG. 6 is a diagram conceptually explaining the state, FIG. 6 is a diagram showing a modification of the multi-nozzle arrangement, and FIGS. 7 and 8 are diagrams showing the configuration of a conventional device. 1... Inkjet nozzle device 3... Sheet-like material 8... Nozzle head array 11... Control device 17... Memory 20...
Nozzle head patent applicant Kanebo Co., Ltd. Toshin Kogyo Co., Ltd.

Claims (2)

[Claims] (1) Print a desired color pattern reproduction image on a sheet-like object such as cloth that is conveyed in the horizontal direction by jetting multiple color print liquids from an inkjet nozzle based on image data obtained by color-separating the original image. In an inkjet printing device, a plurality of inkjet heads each having a plurality of inkjet nozzle holes arranged in a row at an equal pitch are shifted back and forth with respect to the running direction of a sheet-like object to be conveyed, and the plurality of inkjet heads are An inkjet printing device characterized in that the nozzle holes of the head are arranged two-dimensionally so as to cover at least the entire width of a sheet-like object. (2) A patent claim comprising means for extracting printing image data as print data for each nozzle hole, and a memory for storing the extracted print data in one-to-one correspondence with the nozzle holes. The inkjet printing device according to scope 1.