JP2015157389A - Print form correction method of ink jet printer and ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a print form correction method capable of controlling so that rotational angle of a head of an ink jet printer is synchronized with a transportation speed of a printed base material even if the transportation speed of the printed base material changes from a low speed to a high speed, relating to printing on the base material by roll to roll, using the ink jet printer.SOLUTION: In a correction method of print form of an ink jet printer, an ink jet printer head 1 has a configuration capable of rotating relative to a print surface by external control. A drive motor controls so that a rotational angle of a head of an ink jet printer is synchronized with a transportation speed of a printed base material 3.

Description

  The present invention relates to a printing shape correction method when an ID number or code is printed using an ink jet printer when film production is performed at high speed by a roll-to-roll production system or the like.

  The roll-to-roll production method is a manufacturing method capable of performing printing of paper and plastic films, conversion of various packaging materials, and the like at high speed and in large quantities, and is widely used commercially. At present, due to its good productivity, it has been applied to circuit formation as a printing device in the electronics field, and further, it has been developed to advanced technologies such as transfer of ultra-fine patterns such as nanoimprint.

  Against this background, for roll-to-roll production systems, in addition to a demand for speeding up, quality assurance to customers and body management of products being manufactured are demanded.

  As a method for individually managing products in film production, there is a method in which an ID number or a code is printed on a film edge or the like during production in particular, and a product is recognized by a code reader after becoming a product.

  Therefore, even when film production is performed on a high-speed line such as several hundred m / min to several thousand m / min in the roll-to-roll production method, an ink jet printer is used when an individual management serial number is required with an ID number or code. Printing is performed in synchronization with the flow of each product.

  By the way, as a kind of nozzle for injecting ink droplets of an ink jet printer, there are a single nozzle method in which injection and collection are continuously repeated, and a porous line nozzle method in which ink particle filling is repeated every time one line is injected, In any case, it is assumed that the object to be printed is moving at a constant speed, but the former single nozzle is used in the case of high-speed correspondence.

  Using such an ink jet printer, the method of setting the head is basically set so that the printing direction is perpendicular to the film flow direction.

  As a printing mechanism by an inkjet printer, in the case of a single nozzle, ink particles are always ejected continuously from the nozzle. For example, the presence / absence of dots is turned on / off depending on the ID number and code contents that change sequentially at several tens of kHz. It is converted into a signal to control the ejection of ink grains.

  If ink particles ejected continuously are swept at a constant speed in the height direction of characters by the force of static electricity, the dot intervals will be aligned and aligned in a straight line, and the object to be printed is moving at a constant speed. Therefore, when the sweep is repeated, the ink particles are arranged as dots between the lattices and are recognized as an ID number or code print on the product.

  In the roll-to-roll production method, when film production is performed, it is necessary to print ID numbers and codes in sequence for quality assurance to customers and individual management of products being produced. In such a case, an ink jet printer is used, and printing is performed by sequentially changing the ID number and code contents so as to synchronize with the flow of each product.

  Further, when the line speed is increased in the roll-to-roll production method, an inkjet printer having a high frequency for ejecting ink particles is installed.

  As an injection nozzle of an ink jet printer head, there are a single nozzle that repeats injection and recovery continuously and a porous line nozzle, but the latter repeats loading of ink each time one line of ink particles is ejected, Currently, high-speed support is not suitable.

  For this reason, it is appropriate to select a single-nozzle ink jet printer for high-speed lines. However, when printing is performed, the film moves in the flow direction even while ink particles are repeatedly ejected from the nozzle, so printing is not possible. In this case, a certain amount of positional deviation occurs at the beginning and the end of the ink particles arranged in one line, and the ID number and code printing shape are distorted obliquely.

  With such a printed shape, there has been a problem that automatic recognition by a code reader or image processing cannot be performed on the product.

  Also, during production, the conveyance speed (line speed) of the substrate to be printed varies variously from low speed to high speed. In this case, the amount of misalignment is not constant. There was no way to compensate, changing with speed.

  In order to suppress the oblique distortion of printing and maintain the quality of a fixed shape so that the ID number and code can be automatically recognized, it is sufficient to select a film with a sufficiently high injection frequency relative to the speed in the film flow direction. About 100 kHz is the limit, and the printed shape is clearly distorted obliquely, and there is a limit to cope with high-speed lines.

  Although proposals have been made to install the inkjet printer head so that it can rotate, it has not been possible to quantitatively correct the oblique distortion of the print shape that occurs in the high-speed line (Patent Document 1).

  Further, when the conveyance speed of the substrate to be printed is changed from low speed to high speed, the oblique distortion of the ID number and code printing shape also changes. In order to correct this, it is necessary to control the rotation angle of the head of the ink jet printer so as to synchronize with the conveyance speed of the substrate to be printed.

JP 2005-88242 A

  When printing on a substrate by roll-to-roll using an ink jet printer, the rotation angle of the head of the ink jet printer can be changed even if the transport speed of the substrate to be printed changes from low speed to high speed. It is an object of the present invention to provide a printing shape correction method that can be controlled so as to synchronize with each other.

As means for solving the above-mentioned problems, the invention according to claim 1 is a method for correcting a printing shape of an inkjet printer,
The head of the ink jet printer has a structure that can rotate with respect to the printing surface by external control,
A method for correcting a printing shape of an ink jet printer, wherein a rotation angle of a head of the ink jet printer is controlled by a drive motor so as to synchronize with a conveyance speed of a substrate to be printed.

  According to a second aspect of the present invention, the conveyance speed of the substrate to be printed is detected, and the rotation angle of the head of the inkjet printer with respect to the printing surface is controlled in accordance with the conveyance speed. Item 8. A method for correcting a printing shape of an inkjet printer according to Item 1.

According to a third aspect of the present invention, there is provided a relationship between the degree of distortion of the print shape due to the conveyance speed of the substrate to be printed and the rotation angle with respect to the print surface of the head of the ink jet printer for eliminating the distortion of the print shape. Remember,
3. The method of correcting a print shape of an ink jet printer according to claim 1, wherein a rotation angle of the head of the ink jet printer with respect to a print surface is controlled in accordance with a conveyance speed of the print base material.

  The invention according to claim 4 is characterized in that an encoder is installed on the drive roll for detecting the conveyance speed of the substrate to be printed. This is a printing shape correction method for an inkjet printer.

Moreover, in order to take the printing shape correction method of the inkjet printer as described in any one of Claims 1-4, the invention of Claim 5 is used.
A function of rotating the head of the inkjet printer at a desired angle with respect to the printing surface;
A function to detect the conveyance speed of the substrate to be printed by installing an encoder on the drive roll;
A function of storing the relationship between the degree of distortion of the print shape due to the conveyance speed of the substrate to be printed and the rotation angle with respect to the print surface of the head for eliminating the distortion of the print shape;
An inkjet printer having a function of controlling a rotation angle of a head of an inkjet printer by a drive motor so as to synchronize with a conveyance speed of a substrate to be printed.

  According to the present invention, in a roll-to-roll production system using a single-nozzle ink jet printer, ID numbers and codes can be printed at a high speed, and the print shape can be made to have a constant quality. Productivity is improved because the quality can be automatically recognized. Further, since the ID number and code printing on the product can be serialized, quality assurance to the customer and individual management of the product being manufactured can be performed.

It is the conceptual diagram which showed the state which attached the head of the inkjet printer in the printing shape correction method of the inkjet printer of this invention. It is the conceptual diagram which showed the diagonal distortion of the printing shape when the conveyance speed of a printing base material was made into high speed (300 m / min). It is the graph which showed the distortion of the position of the ink grain by the conveyance speed of a printing base material. It is the graph which showed the distortion of the position of an ink grain when rotating the head of an inkjet printer according to the conveyance speed of a printing substrate. FIG. 4 is a conceptual diagram illustrating a print shape in which a head of an ink jet printer is rotated and distortion is corrected in accordance with a conveyance speed of a print substrate. It is the table | surface which showed the relationship between the conveyance speed of a printing base material, and an inkjet head rotation angle. It is the conceptual diagram which showed the change principle of the ink particle orbit of an inkjet head.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram of an ink jet head mounting method according to an embodiment of the present invention. The ink jet head 1 is attached to a frame 2 of the apparatus so that it can be moved in the width direction of the film. Moreover, it is structured to be rotatable with respect to the printing surface, and is driven to rotate at an arbitrary angle by a drive motor by external control.

  When the line is stopped, the printing height direction is set to be perpendicular to the flowing direction of the film as the substrate 3 to be printed.

  A rotary encoder is installed on the drive roll of the apparatus so that the conveyance speed of the substrate to be printed can be constantly monitored, and the conveyance speed of the substrate to be printed is calculated from the output signal so as to be output.

  FIG. 2 shows an example of code printing when the conveyance speed of the substrate to be printed is high. There is a difference 10 in the flow direction of the object between the initial and final ejection of the ink particles ejected in the flow direction 5 of the film, and the print result has an obliquely distorted shape. This print shape cannot be recognized by a code reader or image processing.

  FIG. 3 shows an oblique distortion in the printed form of the code, and is a result of calculating the positions of the ejected ink particles by calculation. It can be seen that when the speed is increased to a low speed of 20 m / min, a medium speed of 150 m / min, and a high speed of 300 m / min, the ink particles are separated from the straight line. If the conditions are the same, the difference 14 matches the difference 10 in FIG.

  FIG. 4 shows the result of the calculation shown in FIG. 3, in which the rotation angle of the head of the ink jet printer is synchronized with the conveyance speed of the substrate to be printed, and the head of the ink jet printer is adjusted so that there is no oblique distortion of the code print shape. This is the result of optimization by rotating a certain angle. By doing so, it can be seen that, for example, even when the speed is increased to a high speed of 300 m / min, the ink particles are arranged substantially in a straight line. The rotation angle at this time was 30 °.

  FIG. 5 shows an example of code printing in which the rotation angle of the head of the ink jet printer is changed with reference to the result of FIG. There is no difference between the initial and final ejection of the ink particles ejected in the flow direction 5 of the object, and as a printing result, the oblique distortion of the printing shape is corrected as shown in FIG. With this print shape, recognition by a code reader or image processing is possible.

  FIG. 7 shows the principle of deflection of the trajectory of the ink grains in the ink jet printer head 1. The ink grains ejected sequentially from the nozzle at a frequency of several tens of kHz are set after the electric charge is applied by the charging electrode 16. When passing through the deflection electrode 17 so that the printing height is several mm, the trajectory is bent and reaches the film surface.

  Since the ink particles are set to be bent in the direction perpendicular to the current film flow direction, when the ink jet printer head 1 is rotated to the film flow direction side, the ink particle arrival point at the upper part of the print height. Can be controlled to synchronize with the transport speed of the substrate to be printed.

  In order to correct the oblique distortion of printing by the ink jet printer at all times on the production line, a table of the conveyance speed of the substrate to be printed and the rotation angle of the ink jet printer head 1 as shown in FIG. 6 from the results of FIGS. Create it.

In actual film production, the inkjet head is controlled to a specific rotation angle according to the table of FIG. 6 while detecting the conveyance speed of the substrate to be printed, and ID numbers and codes are printed.

  The present invention is a method that is useful when the printing object moves at high speed in a scene where printing is performed using an ink jet printer, regardless of the production method, and contributes to an increase in productivity.

  When the object to be printed moves at a high speed, it always accompanies the acceleration / deceleration. It can also be used in a conventional inkjet printer introduction scene, and the production speed is improved.

  In recent years, the importance of product liability and product traceability has increased, and the need for individual management of products being manufactured, including quality assurance for customers, has increased. According to the ink jet, it is possible to change the contents of printing by serial numbers, and it can be used in such a scene.

  Print quality is maintained in high-speed printing by an inkjet printer, and the possibility of automatic recognition by a code reader or image processing can be expanded.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer head 2 ... Inkjet printer head mounting apparatus frame 3 ... Printed substrate (film)
4 ... guide roll 5 ... film flow direction 6 ... printing height 7 ... printing width 8 ... ink grain initial 9 ... ink grain last 10 ... difference 11 ... Low substrate transfer speed (20m / min)
12 ... Medium speed of the substrate to be printed (150m / min)
13 ... High speed of conveyance of substrate for printing (300m / min)
14 ... Difference 15 ... Nozzle 16 ... Charged electrode 17 ... Deflection electrode

Claims (5)

A printing shape correction method for an inkjet printer,
The head of the ink jet printer has a structure that can rotate with respect to the printing surface by external control,
A printing shape correction method for an ink jet printer, characterized in that the rotation angle of the head of the ink jet printer is controlled by a drive motor so as to synchronize with the conveyance speed of the substrate to be printed.   2. The print shape correction of an ink jet printer according to claim 1, wherein a transport speed of a substrate to be printed is detected, and a rotation angle of a head of the ink jet printer with respect to a print surface is controlled in accordance with the transport speed. Method. Storing the relationship between the degree of distortion of the print shape due to the conveyance speed of the substrate to be printed and the rotation angle with respect to the print surface of the head of the ink jet printer for eliminating the distortion of the print shape;
The method for correcting a print shape of an ink jet printer according to claim 1 or 2, wherein a rotation angle of the head of the ink jet printer with respect to a print surface is controlled in accordance with a conveyance speed of the print base material.   The method for correcting a printing shape of an ink jet printer according to any one of claims 2 and 3, wherein an encoder is installed on the drive roll for detecting the conveyance speed of the substrate to be printed. In order to take the printing shape correction method of the ink jet printer according to any one of claims 1 to 4,
A function of rotating the head of the inkjet printer at a desired angle with respect to the printing surface;
A function to detect the conveyance speed of the substrate to be printed by installing an encoder on the drive roll;
A function of storing the relationship between the degree of distortion of the print shape due to the conveyance speed of the substrate to be printed and the rotation angle with respect to the print surface of the head for eliminating the distortion of the print shape;
An ink jet printer comprising a function of controlling a rotation angle of a head of an ink jet printer by a drive motor so as to synchronize with a conveyance speed of a substrate to be printed.