JP2002096014A - Method of forming uniform coating film on outside peripheral surfaces of rolls having different sizes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a uniform coating film on a roll by an ink jet type printer and a method of forming the uniform coating film on the outside peripheral surfaces of the rolls having different sizes. SOLUTION: In the method of forming the coating film by jetting a coating liquid from the ink jet type printer head 5 advancing to the rotatably driven roll 1 and scanning in the roll surface length direction, the roll 1 is rotated at a rotation speed calculated from the outside dimension of the roll 1 and the line forming speed by a controller to make the peripheral speed of the roll 1 coincide with the prescribed line forming speed, at which the line is formed by shifting and overlapping the jetting dot in the roll peripheral direction, and the coating liquid is jetted from the printer head while scanning the printer head 5 in a required spiral state relatively to the roll 1 to form the uniform coating film by making the printer head 5 travel at a traveling speed in the roll surface length direction, which is calculated from the rotation speed of the roll 1, the width of the spiral coating line formed by the dot and the overlapped dimension of the spiral coating lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a uniform coating film on a roll by an ink jet printer, and a method for forming a uniform coating film on the outer peripheral surface of a roll having various sizes.

[0002]

2. Description of the Related Art Conventionally, a method of forming a uniform black film for laser ablation on the outer peripheral surface of rolls of various sizes in flexographic plate making and gravure plate making has been known by using a vertical coating apparatus (for example, Japanese Patent Application Laid-Open No. 60-107950). ). The vertical coater stands upright, chucks both ends, rotates it, rotates it sufficiently by hand, performs degreasing, etc., then stops rotation, and fits a ring-shaped liquid reservoir dish that can move up and down on the upper end of the roll. The black liquid for laser ablation is stored in the dish, and the liquid storage dish is lowered at a slow constant speed to coat the black liquid for laser ablation by dipping. As another coating apparatus, a roller sliding coating apparatus (for example,
No. -107849), which is used for a photosensitive film coating. On the other hand, conventionally, there has been no method or apparatus for forming a uniform coating film on the outer peripheral surface of a roll by an ink jet printer.

[0003]

In order to make all the steps of plate making into a line, it is necessary to provide an in-line apparatus for coating and forming a photosensitive film or a black film for laser ablation. Conventional vertical coaters are not suitable for full automation and in-line. Further, the conventional roller rubbing coater has already been inlined, but it is not possible to control the film thickness to an arbitrary thickness between about 1 micron and about 10 microns. The film thickness is an important variable factor that determines the photosensitive characteristics and laser ablation characteristics, and also a factor that determines the functionality of the etching resist.

In order to solve the above problem, the inventors of the present application have considered a method of forming a uniform coating film on a roll by an ink jet printer, and a method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes. (Unknown). More specifically, a method is considered in which an inkjet printer head scans a roll that is supported at both ends by a chuck rotating means and is driven to rotate in the roll surface length direction, and sprays a coating liquid from the inkjet printer head to form a coating film. (Unknown). However, according to the knowledge of the inventors of the present application, the line forming speed at which lines can be formed by spraying a coating liquid (a photosensitive liquid or a black liquid for laser ablation) from an inkjet printer head, that is, the linear growth per unit time is On the other hand, the line forming speed is a function determined by the size of the dot of the coating liquid applied to the roll surface and the degree of overlap between the dot and the next dot. The size of the dot is determined by the size of the nozzle, the ejection amount, and the gap distance, and the degree of overlap between one dot and the next dot is determined by the moving speed of the printing plate and the timing of the ejection of the coating liquid. For this reason, if the rolls of various sizes are supported at both ends and rotated at a constant rotation speed regardless of the size of the rolls, the dots of the coating liquid are shifted and overlapped with the rolls of the intermediate diameter so that a line is formed. Then, with a roll larger than the intermediate diameter, the peripheral speed is high and the dots of the coating liquid cannot shift and overlap, and the dots are separated one after another, making it impossible to form a line. It was found that the speed was reduced, the dot displacement of the coating liquid was small, and the coating was too thick. Therefore, it was found that the number of rotations needed to be changed according to the size of the roll. However, when changing the rotation speed according to the size of the roll, if the speed of the printer head in the roll surface length direction is kept constant regardless of the size of the roll, the rotation of the roll When the running speed of the printer head becomes too low relative to the rotation speed of the roll by increasing the number, the spiral coating line formed by the dots of the coating liquid and the coating line overlap and the surface coating can be performed. When the running speed of the printer head becomes too high relative to the number of rotations of the roll, it was found that It was found that the spiral painted line formed by the dots and the painted line were separated from each other to form a coil wire, so that the surface coating could not be performed with the dots of the etching resist forming liquid. Accordingly, it is necessary to change the number of rotations of the roll so that the dots can be shifted and overlapped to form a line corresponding to the size of the roll, and the lines can be spirally overlapped to form a surface. It was found that it was necessary to change the speed in the roll surface length direction.

[0005] The present invention has been made in view of the above points, and can form a uniform coating film on rolls of various sizes using an ink jet printer,
In addition, the film thickness can be controlled to an arbitrary thickness in the range of about 1 micron to about 10 microns, and a line for processing rolls of various sizes, specifically, printing for gravure printing or flexographic printing. An object of the present invention is to provide a method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes, which contributes to a line of the entire process of making a roll.

[0006]

According to a first aspect of the present invention, a roll is supported at both ends by chuck rotating means and driven to rotate.
A method of forming a coating film by scanning an ink jet type printer head supported by a two-dimensional table with respect to the roll in the proximity of the roll surface length direction and spraying a coating liquid from the printer head. Based on the outer diameter of the roll, the rotation speed of the roll is adjusted so that the peripheral speed of the roll matches the line forming speed of a predetermined size in which the ejection dots of the coating solution are shifted in the circumferential direction of the roll and overlap to form a line. In addition to calculating the rotation speed of the roll, the width of the spiral coating line formed by the dots, the spiral coating line formed by the dots, and the overlap dimension of the coating line, the traveling speed of the printer head in the roll surface length direction. Is calculated, and the roll is rotated at the calculated rotation speed,
While the printer head is running at the calculated running speed, the coating liquid is sprayed from the printer head to form a uniform coating film on the rolls. An object of the present invention is to provide a method for forming a coating film. In the second invention of the present application, the two-dimensional table supporting the ink jet type printer head is moved closer to the roll supported at both ends by the chuck rotating means, and the printer head is moved closer to the proper ejection gap with respect to the roll, or When approaching a minute distance before the ejection gap, the approach movement of the two-dimensional table is stopped, and the ejection dots of the coating liquid are shifted in the circumferential direction of the roll and overlapped to form a line. The rotational speed of the roll is calculated based on the outer diameter of the roll so that the peripheral speeds of the rolls coincide with each other, and the rolls, both ends of which are supported by the chuck rotating means, are driven to rotate at the rotational speed. A set of dots overlapping in a chain is spirally displaced by approximately one pitch in the circumferential direction of the roll so that one dot at the end partially overlaps The two-dimensional table in the roll surface length direction of the roll from the calculated rotation speed of the roll, the width of the spiral coating line formed by the dots, and the overlap dimension of the spiral coating line and the coating line formed by the dots. When the scanning speed is calculated, the two-dimensional table supporting the ink jet type printer head is scanned in the roll surface length direction at the calculated scanning speed in the roll surface length direction. When the coating liquid is ejected from the printer head while maintaining the gap to form a negative image consisting of a uniform coating film on the roll, and when the printer head is brought closer to the roll by a small distance to become the proper ejection gap. Is
The outer circumference of rolls of various sizes, characterized in that the printer head is brought closer to the rolls and the coating liquid is sprayed from the printer head while maintaining a proper spray gap to form a uniform coating film on the rolls. An object of the present invention is to provide a method for forming a uniform coating film on a surface. The third invention of the present application
The inkjet printer head and gap sensor are arranged side by side and supported on a two-dimensional table, and the two-dimensional table is moved closer to the roll supported at both ends by the chuck rotating means, and the gap sensor is used to precisely measure the gap with the roll. When the gap between the printer head and the roll is detected via the printer head and approaching to a value slightly larger than the proper ejection gap, the approach movement of the two-dimensional table is stopped, and then the roll is driven to rotate and the printer head is moved. The printer head is spirally scanned relative to the roll by scanning in the direction of the roll surface length of the roll, and the printer head is further brought closer to the roll to maintain an appropriate ejection gap and start spraying the coating liquid to start printing. Spray the coating liquid from the head to form a uniform coating film on the roll Wherein the size to form a uniform coating film on the outer peripheral surface of the various rolls that. As the first, second, and third inventions of the present application, preferably, an inkjet printer head is supported on a two-dimensional table so as to be finely movable in the diameter direction of the roll, and the eccentricity of the roll before the start of spraying the coating liquid. Measure the whirling, input data to the controller, and vibrate the micro-vibration device at the controller to perform calculations to correct the eccentricity and whirling of the roll. An object of the present invention is to provide a method for forming a uniform coating film on the outer peripheral surface of a roll having various sizes, wherein the printer head is held at an appropriate ejection gap with respect to the roll by vibrating the apparatus. Preferably, the first, second, and third inventions of the present application preferably support the printer head on a Y table that can be slightly moved in the diameter direction of a roll provided on a two-dimensional table, and shift the Y table toward the roll. When the coating liquid is ejected from the printer head and the nozzle surface of the printer head is cleaned during the ejection, the printer head is separated from the roll by stopping the movement of the two-dimensional table and retracting the Y table. The cleaning device provided on the two-dimensional table is operated to clean the nozzle surface of the printer head, and thereafter, the Y table is shifted to the whole body position to restart the injection. An object of the present invention is to provide a method for forming a uniform coating film on the outer peripheral surface of a roll. A specific and preferred invention of the present application is to provide a two-dimensional table in which a printer head is supported on a two-dimensional table, and a gap sensor is arranged on the printer head and supported on the two-dimensional table. The gap between the printer head and the roll is adjusted to a value slightly larger than the proper ejection gap by accurately moving the gap between the roll and the roll by the gap sensor. As soon as possible, the movement of the two-dimensional table is stopped, and then, before the start of spraying the coating liquid, the eccentricity and whirling of the roll are measured with a gap sensor, and the data is stored by the controller and the roll is rotated. Calculate the genuine diameter and, based on this, the outer diameter of the roll and the line forming space. The rotation speed of the roll is calculated so that the peripheral speed of the roll matches the required linear forming speed of the coating solution ejected from the printer head from the printer, and the rotation speed of the roll and the coating solution ejected from the printer head are further calculated. Calculate the traveling speed of the printer head in the roll surface length direction from the line width at the time of forming the line, the line of the coating solution and the overlap dimension of the line, and then reciprocate the two-dimensional table along the roll to obtain the gap. The printer detects the position and length of both ends of the roll by a sensor, and then rotates the roll at the rotation speed and vibrates the micro-vibration device corresponding to the eccentricity and whirling of the roll, thereby setting the printer at the standby position before the start of injection. The head is moved further closer to the roll to maintain the proper ejection gap, and the printer head is moved in the roll surface length direction at the above-mentioned running speed, and While scanning the intermediate head relative to the roll in a required spiral shape, a coating liquid is sprayed from the printer head in accordance with the negative image data to form a negative image of the etching resist having a uniform film thickness on the roll, When cleaning the nozzle surface of the printer head during ejection, stop the movement of the two-dimensional table and retract the Y table to separate the printer head from the roll and operate the cleaner device provided on the two-dimensional table. Cleaning the nozzle surface of the printer head, and then shifting the Y table to the whole body position and restarting the jetting. A uniform coating film is formed on the outer peripheral surface of rolls of various sizes. It is to provide a method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes according to the present invention is based on a method in which the outer peripheral surface is coated with a copper-based plating, a nickel-based plating, or a zinc-based plating. It can be applied to a method of forming a photosensitive film or a laser ablation black film that is a uniform coating film on a gravure printing roll that has been polished and mirror-polished,
Alternatively, the present invention can be applied to a method of forming a black film for laser ablation, which is a uniform coating film, on a plate making roll whose outer peripheral surface is covered with an unexposed photosensitive flexo material. FIG. 1 is a schematic plan view of a full-surface coating apparatus for performing a method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes according to an embodiment of the present invention. In FIG. 1, various sizes, e.g.
00mmφ ~ 300mmφ and length L is 800mm ~ 15
A roll 1 intended for a gravure printing roll or a flexographic printing roll of 00 mm includes a spindle chuck 2 rotated by a servomotor 4 and a single-axis table device 1.
Both ends are horizontally chucked by a tail chuck 3 which is pivotally supported by a slide shaft 17d and is movable by, for example, 900 mm in the direction of arrow X. The rotation of the servo motor 4 is a mechanism for transmitting the rotation without backlash, for example, the bevel gear 1
The power is transmitted to the spindle chuck 2 via the meshing rotations of the shafts 3 and 14.

The controller 11 sends a signal to a motor driver (not shown) to feedback-control the servo motor 4 via the motor driver to rotate the spindle chuck 2 in the direction of arrow 18. When the spindle chuck 2 rotates, the controller 11 inputs a pulse signal of a rotary encoder 16 provided directly connected to the spindle chuck 2 to calculate a rotation position (angle), rotation number, and rotation speed of the spindle chuck 2. Thus, the servo motor 4 is feedback-controlled.

The single-axis table device 17 includes a bracket 17
Both ends of a are guided by a pair of guides (not shown), and a ball screw (not shown) is screwed into a ball nut (not shown) fixed to the center of the bracket 17a. By being rotated, the bracket 17a is movable by, for example, 900 mm in the X direction (the surface length direction of the roll 1), and is axially guided by a linear guide 17c in a bearing block 17b provided on the bracket 17a in a non-rotatable manner. The tail chuck 3 is pivotally supported by the slide shaft 17d, and a coil spring 17e biases the slide shaft 17d toward the spindle chuck 2.
Before the roll 1 is chucked, the single-axis table device 17 is at a standby position separated from the spindle chuck 2. When the roll 1 is supported by the industrial robot and one end is engaged with the spindle chuck 2, When the tail chuck 3 moves and engages with the other end of the roll 1 to compress the coil spring 17e as required, the proximity sensor 17f provided on the side of the linear guide 17c detects the detection block 17g provided on the side of the tail chuck 3. Is detected by the controller 11, and the servo motor that rotates the ball screw stops driving.

A two-dimensional table 7 which stands by at a standby position beside the spindle chuck 2 supports an ink jet type printer head 5 and supports the X direction (the surface length direction of the roll 1) and the Y direction (the direction of the roll 1). (Diameter direction). A Y-direction table 8 is provided on the two-dimensional table 7, and the printer head 5, which is engaged and guided by a Y-direction guide 9 provided on the Y-direction table 8,
Is connected to the other end of the micro-vibration device 10 having one end fixed thereto, and the controller 11 electrically controls the micro-vibration device 10 so that the printer head 5 approaches or separates from the roll 1 by several μmm or more. The distance of several hundred μmm can be varied steplessly at a very high speed. The microvibration device 10 uses an electrostrictive actuator such as a piezo element or a voice coil. The Y table 8 is shifted closer to the roll on the two-dimensional table 7 except when cleaning the nozzle surface of the printer head 5. A cleaning device 12 is provided on the two-dimensional table 7 to clean the nozzle surface of the printer head 5 during the ejection. The cleaning device 12 has a two-dimensional table 7 for the Y table 8.
When shifting to the upper side opposite to the roll side, the nozzle surface of the printer head 5 is cleaned by sliding back and forth in the X direction.

The two-dimensional table 7 includes a printer head 5
The gap sensor 6 facing the roll 1 is provided adjacent to the roll 1. The controller 11 performs feedback control of a servo motor (not shown) for moving the two-dimensional table 7 in the X direction and a servo motor (not shown) for moving the two-dimensional table 7 in the Y direction via corresponding drivers (not shown). ing. Also, the controller 11
Is designed to calculate the size of the roll 1 by inputting a signal from the gap sensor 6 and output a control signal corresponding to the size of the roll 1 to each servomotor. Further, the controller 11 outputs an electric signal for ejecting the ejection liquid to the printer head 5.

The bracket 17a of the single-axis table device 17
And the two-dimensional table 7 is reciprocally movable in the X direction (the surface length direction of the roll 1) and the Y direction (the diameter direction of the roll 1). For such a configuration, an appropriate mechanism capable of performing precise movement can be adopted. When the roll 1 is not the sleeve type shown but a shaft type, the chuck structures of the spindle chuck 2 and the tail chuck 3 are different.

The printer head 5 contains a photosensitive liquid, a black liquid having sufficient adhesion to the roll surface and corrosion resistance, or a rust preventive such as 2-ethyl-4-methylimidazole or thiazole. And preferably, a cartridge tank for storing a liquid which is colored in white or the like which can be clearly distinguished from the metal color of the roll so that plate inspection can be performed, and which reacts instantaneously with the metal on the roll surface to form a corrosion-resistant chemical conversion film. An ejection nozzle is provided for ejecting the black liquid supplied from the cartridge tank. As shown in FIG. 3A, the printer head 5 has a required diagonal arrangement such that, when delaying the injection timing from each nozzle, the injections can be overlapped in a horizontal line in a chain. And in a plurality of arrays. In the printer head 5, the tank in the head may be connected to a large-capacity tank through a flexible hole. It is preferable to select a gap sensor 6 having a performance capable of measuring a gap (distance from an object to be measured) in units of 1 μmm. As the two-dimensional table 7 moves closer to the roll 1, the gap sensor 6 detects the gap with the roll 1 as a change in the electric signal, and the controller 11 performs a calculation to convert the distance into a distance.

An annular dial gauge 15 is fixed to the outer periphery of the spindle chuck 2. The master tool 15 is preferably chrome-plated on the outer peripheral surface, and is mirror-finished on the outer peripheral surface with extremely high roundness accuracy so as to have a diameter of, for example, 301.000 mmφ at a room temperature of 25 ° C. The apparatus is positioned in an extremely precise concentric state with the axis of the spindle chuck 2 and is fixed to a frame (not shown).

The printer head 5 is arranged as follows: P1⇒P2⇒P3⇒P4
⇒P5⇒P6⇒P7⇒P8⇒P9⇒P10⇒P1 sequentially move to each point. Except for the movement from P7 to P8, the movement is accompanied by the movement of the two-dimensional table 7. The movement from P7 to P8 is accompanied by the movement of the micro-vibration device 10. In addition, the printer head 5 moves with the backward movement of the Y-direction table 8 when cleaning the nozzle surface.

The point P1 is a standby position of the printer head 5. The operation of moving from the point P1 to the point P2 by moving the stroke a in the Y direction is for precisely measuring the distance from the axis of the spindle chuck 2 to the nozzle surface of the printer head 5. Gap sensor 6
Is retracted from the nozzle surface of the printer head 5 by G μmm, for example, 500 μmm, and the diameter Dm
When the movement of the two-dimensional table 7 is stopped when the gap sensor 6 approaches the master gauge 15 having a diameter of 301.000 mm so that the gap B1 becomes 1500 μmm, the printer head 5 at the point P2 from the axis of the spindle chuck 2 is stopped. The distance A2 to the nozzle surface is (Dm /
2) + B2 = 151.500 mm. B2 is a gap from the nozzle surface of the printer head 5 to the master gauge 15, and B2 = B1-G. As described above, the controller 11 controls the gap sensor 6 to
5 and move to the gap sensor 6 and master gauge 1
5 is input from the signal of the gap sensor 6 to calculate and store the data.
From the diameter Dm of the gap, the gap G between the gap sensor 6 and the nozzle face of the printer head 5, and the gap B1 of the gap sensor 6 with respect to the master gauge 15, A2 = (Dm /
2) + B1−G) The calculation is performed to calculate and store the distance A2 from the axis of the spindle chuck 2 to the nozzle surface of the printer head 5 at the point P2. When the printer head 5 moves by a stroke b in the X direction from the point P2 and
When reaching the point, the roll 1 is moved to a tail chuck side of, for example, 300.000 mm from the end face of the spindle chuck 2 side.

The printer head 5 moves from the point P3 by a stroke c in the Y direction to the point P4. Specifically, the diameter D of the roll 1 is set to, for example, 280.00.
Assuming that the distance is 0 mm, the printer head 5 moves in the Y direction from point P3 to point P4, and stops moving the two-dimensional table 7 when the gap sensor 6 approaches the roll 1 so that the gap becomes 1500 μmm ( 2), the stroke c is 10.500 mm, and the roll 1 of the printer head 5 at the point P4
Is 1000 μmm. in this case,
The diameter D of the roll 1 is the measured dimension, and the distance A2 from the axis of the spindle chuck 2 to the nozzle surface of the printer head 5 at the point P3 has already been measured when approaching the master gauge 15 as described above. , 151.
500 mm. The controller 11 inputs a signal such as a rotary encoder or a linear scale (not shown) and stores the stroke c. Therefore, the controller 11 can calculate the provisional diameter of the roll 1 by calculating (A2−c−1000 μmm) × 2. If the roll is eccentric, this diameter is not an accurate value (FIG. 2).

Note that, from the axis of the spindle chuck 2, P
Distance A1 to the nozzle surface of the printer head 5 of 1 point
When the amount of movement in the Y direction can be measured very precisely using a linear scale or the like, the master gauge 15 is unnecessary,
The printer head 5 may move by the stroke b in the X direction and then by the stroke a + c in the Y direction and move to the point P4. At this time, the controller 11
Can calculate the diameter D of the roll 1 by calculating A1- (a + c) -1000 .mu.mm.

However, in order to calculate the diameter D of the roll 1 more accurately, it is necessary to consider the eccentricity and whirling of the roll 1. The eccentricity of the roll 1 is about 30 μmm at the maximum, and when the roll 1 is rotated once, whirling occurs, and the gap between the roll 1 and the printer head 5 is 60 μmm.
Fluctuations occur. As described above, the movement of the two-dimensional table 7 is stopped when the printer head 5 reaches the point P4 and approaches so that the gap of the gap sensor 6 with respect to the roll 1 becomes 1500 μmm. Subsequently, the roll 1 makes one rotation. At this time, the controller 11 inputs data of a change in the gap of the gap sensor 6 with respect to the roll 1 caused by the eccentricity and whirling of the roll 1. While the roll 1 makes one rotation, the controller 11
For example, a gap that changes every 1/360 rotation is input, and the maximum gap or the minimum gap is picked up from the obtained input data. At this time, the maximum gap and the minimum gap are selected so as to be shifted by 180 degrees, and, for example, a shift angle α between the minimum gap and the origin position (the origin position of the rotary encoder 16) is calculated (see FIG. 2). . The controller 11 calculates (maximum gap + minimum gap) ÷ 2 to calculate an average gap, and then
By calculating (A2-c-average gap) × 2,
A precise diameter D of the roll 1 taking into account the eccentricity and whirling of the roll 1 is calculated. The diameter D of the roll 1 may be calculated using a separately provided diameter measuring device. For example, the controller 11 sorts the data from the position of the minimum gap into data for one rotation, compares each data with the average gap, and when the data gap is larger than the average gap, the roll 1 approaches the gap sensor 6. Since it has come out, the amount of movement of the micro-vibration device 10 away from the roll 1 by the deviation between the average gap and the data gap is stored as, for example, a negative value (−δ). Roll 1 when is small
Is retracted with respect to the gap sensor 6, so that the minute vibration device 1
0 is stored as, for example, a positive value (+ δ) as a movement amount for approaching the roll 1. The gap of 1500 μmm with respect to the roll 1 of the gap sensor 6 when the two-dimensional table 7 stops moving is not an average gap. The 1500 μm gap may correspond to a maximum gap or a minimum gap.

When the print head 5 moves by a stroke d in the X direction from the point P4 and reaches the point P5, the tail sensor 3 of the roll 1 is detected by the gap sensor 6.
The end face of the roll 1 is detected by the gap sensor 6 near the end of the stroke when the print head 5 is moved by the stroke e in the opposite direction and reaches the point P6,
Accordingly, the length L of the roll 1 is calculated and stored by the controller 11, and then the print head 5 is again moved by the stroke f in the opposite direction so that the tail chuck is, for example, 10 mm wider than the end face of the roll 1 on the spindle head 2 side. It stops when it reaches the P7 point on the 3rd side. This position is a standby position before the start of injection. When the print head 5 is stopped at the point P7, as described above, the roll 1 is rotated once to calculate the average gap or to move the micro-vibration device 10 away from or close to the roll 1. The calculation may be performed.

Next, when the print head 5 reaches the point P7, the roll 1 is rotated, the two-dimensional table 7 is moved by the stroke h in the X direction, and the print head 5 starts inkjet. When ink jet is performed, the gap between the print head 5 and the roll 1 is set to an appropriate ejection gap of, for example, 150 μm even though the roll 1 is eccentrically swirled by vibrating the micro-vibration device 10.
mm. When the average gap is calculated as, for example, 1480 μmm, the gap between the gap sensor 6 and the print head 5 is 500 μmm (the numerical value in the above specific example).
When the micro-vibration device 10 is driven closer to the roll 1 by 830 μm from the state where the point is located, the gap between the print head 5 and the roll 1 becomes 150 mm.
Although it is μmm, it cannot be maintained at 150 μm unless the micro-vibration device 10 vibrates in response to the eccentricity and whirling of the roll 1. Therefore, in order to always keep the gap between the print head 5 and the roll 1 at an appropriate ejection gap of 150 μmm, the movement amount of the micro-vibration device 10 to be shifted forward by 1/360 rotation for one rotation of the roll 1 in advance. Is calculated and stored. Then, a value obtained by adding 830 μmm to each movement amount (−δ or + δ) for moving the micro-vibration device 10 away or close to the roll 1 corresponding to one rotation of the roll 1 calculated as described above is obtained. The controller 11 calculates and stores the amount of movement of the micro-vibration device 10 to be shifted forward at every 1/360 rotation, and stores the calculated amount. When the micro-vibration device 10 is output and vibrated, the print head 5 can be vibrated so that the gap between the roll 1 and the roll 1 becomes an appropriate ejection gap, for example, 150 μm, despite the eccentric rotation of the roll 1. it can. Before the jetting, the roll 1 is rotated at, for example, 10 rpm and the print head 5 is moved by 50 mm per rotation, so that the print head 5 is relatively spiraled from one end of the roll 1 to the other end. At this time, the signal of the rotary encoder 16 is set to, for example, 15 ° with respect to the origin signal.
Each time the rotation advances, a signal is input to the controller 11, the gap of the gap sensor 6 with respect to the roll 1 at the time of each signal input is measured, and the entire eccentricity / contact state of the roll 1 is input to the controller 11 as data.
In 1, in order to keep the gap constant, the amount of movement of the micro-vibration device 10 to be moved forward and backward may be calculated, and the micro-vibration device 10 may be moved forward and backward during injection. Also, since the rotation of the roll 1 is slow, the gap sensor 6 measures the gap with respect to the roll 1 and controls the micro-vibration device 10 in real time to
Can be made constant to be 150 μmm. Further, the proper ejection gap for the print head 5 and the roll 1 is not fixed at 150 μmm. As described above, the diameter D of the roll 1 and the shift amount for vibrating the micro-vibration device 10 are calculated in consideration of the eccentricity and whirling of the roll 1.

When the print head 5 reaches the point P7 and starts ink jetting, the roll 1 rotates at the rotation speed calculated by the controller 11: Nr.pm, and the print head 5 moves at the speed calculated by the controller 11: Stroke h in X direction at Vμmm / min
Just move.

When calculating the diameter D of the roll 1 in consideration of the eccentricity and whirling of the roll 1, the controller 11 calculates the diameter D of the roll 1 based on the diameter D and the line forming speed H.
Is calculated so that the peripheral speed of the roll 1 matches the linear forming speed H of the liquid jetted from the printer head 5, and then corresponds to the calculated rotation speed Nr.pm of the roll 1. Then, the traveling speed Vmm / sec of the printer head 5 in the roll surface length direction is calculated. <Calculation> Regardless of the roll diameter D, the rotation speed Nr.pm at which the peripheral speed always becomes a predetermined value is calculated. The dot diameter R is determined by the diameter of the nozzle provided in the printer head 5 and the degree of spread of the jet. The line width R is determined by the number of nozzles provided in the printer head 5.
When the number of nozzles is one, the line width R is the dot diameter Q if the line-to-line overlap dimension is calculated separately.
(Μmm). When there is only one nozzle, it takes too much time and is not practical. Therefore, as many nozzles as possible are provided in an oblique array as shown in FIG. 3 (a) and delay processing is performed, so that the ejection dots are shifted in a row like a horizontal line as shown in FIG. 3 (b). The configuration is as follows. The size of the dots that overlap in order to form lines in the roll surface length direction is 0.35Q to 0.5Q, and the size that the dots overlap in order to form dots in the roll circumferential direction is 0.35Q to 0.5Q. In addition,
The dimensions 0.35Q to 0.5Q that overlap the dots are
It is preferable that a desired value can be input from an input device (not shown) attached to the controller 11. Controller 11
Is the distance H (μmm) at which dots form lines in one minute,
The number of times the liquid is ejected per minute (= the number of times a signal for performing the liquid ejection is output) K, the dot diameter Q (μmm), and the dimension 0.35Q at which the dots overlap in the roll circumferential direction
From 0.5Q, H = ｛K ・ Q- (K-1) ・ 0.35Q ～
(Constant value) can be calculated from the formula of 0.5Q｝. When the diameter D of the roll 1 is measured or input, the controller 11 precisely calculates the circumferential length S from the formula of S = D × π to the unit of 1 micron. Therefore, the controller 11
= N × S = N × D × π, a modified form of the relational expression, N = H /
(D × π) = {K · Q− (K−1) · 0.35Q to 0.5Q} /
From (D × π), the roll 1 corresponding to the diameter value D of the roll 1
Is calculated. Decide K and Q, H =
Calculating {K · Q− (K−1) · 0.35Q to 0.5Q} is a specific development design problem. Some commercially available ink jet printers have a printer head speed H of 400 to 500 mm per second at high speed.

Since the rotation speed N is changed according to the size of the roll 1, the running speed V of the printer head 5 in the roll surface length direction is changed accordingly. The reason is that, as described in the section of the related art, when the rotation speed N is changed according to the size of the roll 1, regardless of the size of the roll 1, When the rotation speed of the roll 1 is too high, the spiral coating line formed by the dots of the jet liquid and the coating line overlap and the surface coating can be performed when the rotation speed of the roll 1 is too high, but the deviation is small and the coating is thick. It becomes too much, it is impossible to secure the desired film thickness,
Also, if the number of rotations of the roll is too small, the spiral painted line formed by the dots of the jet liquid and the painted line will be separated,
This is because the surface coating cannot be performed with the dots of the jet liquid. Therefore, as shown in FIG. 3 (c), when the roll 1 is rotated once, the position of the liquid jet is slightly overlapped with the position of the liquid jet one rotation before without opening a gap, and the spiral shape is shifted. The printer head is caused to scan in the roll surface length direction so as to perform liquid ejection. <Calculation> The equation for calculating the line width R when a plurality of nozzles are provided as n is R = {n · Q− (n−1) · 0.35Q to 0.5
Q｝. The overlap dimension between the lines of the jet liquid is preferably equal to the dimension 0.35Q to 0.5Q at which the dots overlap. The traveling speed V of the printer head 5 in the roll surface length direction includes a rotation speed Nr.pm of the roll 1, a line width R (μmm) when the liquid ejected from the printer head 5 forms a line, and a line of the liquid ejected. And the overlap dimension of the line is calculated by the following equation. V (μmm / min) = ｛NR- (N-1) 0.35Q-0.
5Q｝

[0025]

[Estimation Example] When the linear forming speed H is 400 mm / sec, the diameter D of the roll 1 is 30
When the diameter is 0 mm, it needs to be approximately 25.46 rpm, and when the diameter D of the roll 1 is 200 mm, it is approximately 3
It is required to be 8.19 rpm, and when the diameter D of the roll 1 is 100 mm, it needs to be approximately 76.39 rpm. The data of the negative image is a data group corresponding to each rotation of the roll, and the data output per rotation is allocated and output based on the signal of the rotary encoder corresponding to the rotation angle of the roll, and the image is formed in a spiral shape. In order to prevent deviation, the rotation speed N is set to a good numerical value for the servo motor 4, and the roll 1 of the servo motor 4 is 25 r.p.
m, 40 rpm, and 75 rpm. The error due to this is absorbed as a very small deviation of the dot overlap, and the image expands or contracts in the circumferential direction, albeit very slightly. Therefore, for example, assuming that the amount of overlap between the nozzles is 0.5Q, a jet having a diameter of 8 μmm is formed by jetting the jet liquid from one nozzle at, for example, 4 picoliters, and the line width R when 100 nozzles are provided is It is 404 μmm from the above equation for determining R. As described above, when the diameter D of the roll 1 is 300 mm, 25
When the rotation speed is 200 rpm, the rotation speed of the printer head 5 in the roll surface length direction is 40 m.
m is 10004 μmm / min, 200 mm is 16004 μmm / min, and 100 mm is 30004
Since it is necessary to set the speed to μmm / min, the controller 11 moves the two-dimensional table 7 in the direction of the surface length of the roll 1 at the calculated speed. When the moving speed of the roll 1 of the two-dimensional table 7 in the surface length direction is set to a good value for cutting, the speed is roughly reduced so that the line does not separate from the line. In the above calculation example, when the roll surface length is 1.2 meters, when the diameter D of the roll 1 is 300 mm, it is about 119 minutes, when it is 200 mm, about 75 minutes, 100 m
In the case of m, a negative image can be applied and formed on the entire surface of the roll in about 40 minutes. Since the time is long in this case, the time can be reduced by providing a printer head having 200 to 300 nozzles or by providing a plurality of printer heads. If the diameter of the nozzle is increased, the screen width of the non-image portion of the shadow portion becomes too large when it is desired to perform high-definition printing with 300 screen lines per inch. Is preferably increased.

As shown in the above calculation example, when the diameter D of the roll 1 is 300 mm, the rotational speed is 25 rpm, and the diameter D of the roll 1 is 25 rpm.
Must be 40 rpm when the diameter is 200 mm and 75 rpm when the diameter D of the roll 1 is 100 mm. It is difficult to rotate precisely,
An intermittent transmission is interposed between the servo motor 4 and the drive side spindle 2, and the servo motor 4 is driven to rotate at an approximate value before the injection. It is preferable that the number of revolutions be measured by a tachogenerator capable of taking out a number and corrected so as to be the required number of revolutions, and then the injection be performed.

When the printer head 5 reaches the point P7, the controller 11 drives the servo motor 4 to rotate the roll 1 at the calculated rotation speed Nr.pm, and causes the micro-vibration device 10 to vibrate minutely to cause the printer 11 to vibrate. The head 5 is moved closer to the point P8, and then the two-dimensional table 7 is started to move in the X direction at the above calculated speed V (μmm / min), and the printer head 5 is rotated by one rotation for each rotation. The jet liquid is jetted to the roll 1 in accordance with the origin signal of the encoder 16). As shown in FIG. 4, the negative image is a spiral line formed by dots when the inkjet head is started and the inkjet head is rotated once after the inkjet head is rotated in accordance with the rotation origin of the spindle chuck 2 (origin signal of the rotary encoder 16). Are shifted by one pitch without any gaps next to each other. The difference between the last dot of one rotation and the first dot of the next rotation is
Since the dimensions are odd, if R is in the range of 1.7.Q to 0.35.Q, no pinhole will occur. Printer head 5
Is slightly vibrated by the micro-vibration device 10 and the roll 1 that rotates eccentrically and oscillates, for example,
By moving from the point P8 to the point P9 while maintaining an appropriate gap of 50 μmm, a negative image of the etching resist can be formed on the roll 1. Note that, unlike a coat for forming a negative image or a positive image, dots may be shifted at the origin position in the rotation direction.

When the printer head 5 reaches the point P9, the ink jet stops and the micro-vibration device 10 stops the micro-vibration and stops. The two-dimensional table 7 moves in the Y direction by a stroke a + c and the Y-table 8 moves. When the robot moves backward and moves only by the stroke i, it reaches the point P10, and when it moves by the stroke j in the X direction, it returns to the point P1 of the original standby position.

In order to clean the nozzle surface of the printer head 5 during the ejection of the ejection liquid from the printer head 5, the controller 11 counts the number of ejections, and when the number reaches a certain number, the controller 11 matches the origin position of the rotary encoder 17. To suspend the injection, and at the same time,
Is stopped, and the controller 11 stores the movement stop position of the two-dimensional table 7 in the X direction. Then, as shown in FIG. 5, while the two-dimensional table 7 is stopped, Y
By retracting the table 8, the printer head 5 is separated from the roll 1 by, for example, 20 mm, and the two-dimensional table 7 is separated.
Is reciprocated in the X direction to wipe off the ink that rebounds and adheres to the nozzle surface of the printer head 5 with the ink absorbing mesh body 12a, and then moves the Y table 8 to the original forward position. Then, the two-dimensional table 7 is precisely moved to the spindle chuck 2 side by, for example, 1000 μmm and stopped, and from here, the two-dimensional table 7 is restarted to move in the direction of the tail chuck 3 and moved by 1000 μmm. By this time, the rising time of the motor rotation speed is passed, the original constant speed is reached, and the injection is restarted at the time when the motor has moved by 1000 μm and coincident with the origin position of the rotary encoder 17.

According to the present invention, as described above, the rotation speed N of the roll 1 is changed according to the size of the roll 1 and the running speed V of the printer head 5 in the roll surface length direction is changed. When a jet liquid is ejected from the printer head 5 while scanning the printer head 5 relative to the roll 1 in a required spiral shape, a uniform coating film can be formed on the roll 1. The controller 11 performs interpolation control of signals for performing rotation scanning of the roll 1, movement scanning of the printer head 5, and ejection of the printer head 5.

The method of the present invention can be applied to a step of spraying a coating liquid to form a coating film having a uniform thickness and a desired film thickness over the entire surface. Specifically, the method can be adopted inline in the following steps. (1) Using a flexo plate making method, a photosensitive resin layer is formed on the base roll.
In the process of round processing ⇒ light-shielding black film coating ⇒ laser ablation / positive exposure / negative mask image formation ⇒ whole surface exposure ⇒ negative mask image removal ⇒ development (resin etching) process, adopted in the process of coating the roll with a light-shielding black film on the whole surface it can. (2) In the gravure plate making method, the base roll goes through copper plating or zinc plating ⇒ round processing ⇒ shading black film coating ⇒ laser ablation, positive exposure, negative image etching resist formation ⇒ etching ⇒ resist removal ⇒ chrome plating In the process, it can be adopted in the step of coating the entire surface of the roll with a light-shielding black film. (3) Gravure plate making method, copper plating on base roll ⇒ round processing ⇒ photosensitive film coating ⇒ laser exposure / negative image latent image formation ⇒
In the process of developing → etching / positive cell formation → resist removal → chrome plating, the process can be applied to the whole process of coating the roll with a photosensitive film.

According to the above-described method of the present invention, the printer head 5 and the gap sensor 6 are arranged side by side to form a two-dimensional table 7.
, The two-dimensional table 7 is moved closer to the roll 1 that is supported and rotated by both ends by the chuck rotating means, and the gap between the two-dimensional table 7 and the roll 1 is precisely measured by the gap sensor 6. When the gap with respect to the roll 1 is approached so as to be slightly larger than the proper ejection gap, the movement of the two-dimensional table 7 is stopped, and then, before the ejection of the ejection liquid starts, the eccentricity and whirling of the roll 1 are reduced. Measured by the gap sensor 6, the controller 11 stores the data and calculates the true diameter of the roll 1 based on the data.
The rotation speed N of the roll 1 is calculated from the above and the line formation speed H so that the peripheral speed of the roll matches the required line formation speed H of the jetting liquid ejected from the printer head 5. The traveling speed of the printer head 5 in the roll surface length direction is obtained from the speed N, the line width R when the jetting liquid ejected from the printer head 5 forms a line, and the overlap dimension of the jetting line 0.35Q to 0.5Q. Calculate V,
Next, the two-dimensional table 6 is reciprocated along the roll 1 to detect both end positions and the length L of the roll 1 by the gap sensor 6, and then the roll 1 is rotated at the rotation speed N and the eccentricity of the roll 1 is detected. By vibrating the micro-vibration device 10 in response to the whirling, the printer head 5 at the standby position before the start of injection is brought closer to the roll 1 to maintain an appropriate ejection gap, and the printer head 5 is moved at the traveling speed V. , And while the printer head 5 scans in a required spiral shape relative to the roll 1 while spraying a jet liquid from the printer head 5 to coat the roll 1 with a uniform film thickness. It forms a film.

[0033]

As described above, according to the method of the present invention for forming a uniform coating film on the outer peripheral surface of a roll having various sizes, it does not belong to any conventional coating film forming method. It is possible to select a roll having a uniform thickness and the same thickness for various rolls by an ink jet printer, in a thickness range of 1 μm to several tens μmm, and in a unit of 1 μmm to several μmm to obtain a desired thickness. No matter what the size of the roll, the roll can be coated uniformly and over the entire surface, and the roll can be handed over in terms of structure. Specifically, plate making for gravure or flexographic printing Contributes to the production of all processes.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an ink-jet type printer apparatus for carrying out a method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes according to the present invention.

FIG. 2 is an explanatory diagram for inputting data of roll diameter, eccentricity and whirling.

FIG. 3A shows an obliquely arranged state of 30 nozzles,
(b) shows a state in which 30 dots are overlapped in a row in a row by ejecting one dot of the ejection liquid from each of the 30 nozzles to the roll by delaying the ejection timing. ) Indicates an overlapping state of spiral painted lines formed by 30 dots.

FIG. 4 is an enlarged view of a portion IV in FIG. 3, which is rotated once by a pitch and shifted by one pitch in a spiral with respect to a position of a dot which coincides with the rotation origin of the spindle chuck and starts inkjet printing. A state in which the spiral line of the set of formed dots overlaps the spiral line of the previous one rotation without a gap, and the circumferential direction of the last dot of one rotation and the first dot of the next rotation (dots matching the rotation origin) FIG.

FIG. 5 is a schematic plan view illustrating a state in which the printer head is cleaned.

[Explanation of symbols]

1 ... roll, 2 ... spindle chuck, 3 ...
・ Tail chuck, 4 ・ ・ ・ Direct servo motor,
5 ... inkjet printer head, 6 ...
Gap sensor, 7: two-dimensional table, 8: Y
Table, 9: Linear guide, 10: Micro vibration device, 11: Controller, 12: Cleaner device, 12a: Mesh body, 13, 14, Rotation transmission mechanism (bevel gear) , 15 ... master gauge,
16 rotary encoder, 17 single-axis table device, 17a bracket, 17b bearing block, 17c linear guide, 17d slide shaft, 17e coil spring, 17f ... Proximity sensor, 17g ... Detection block,

Claims (6)

[Claims] 1. A roll is rotatably driven with both ends supported by chuck rotating means, and an appropriate number of nozzles are provided in a plurality of diagonal arrays to perform a delay process corresponding to a positional shift and to apply a coating liquid from each nozzle. An ink jet printer head capable of ejecting a coating liquid so as to form a strand (line width) overlapping in a row in the roll surface length direction by ejecting the ink is scanned in the roll surface length direction close to the roll. And forming a coating film by spraying a coating liquid from a printer head, wherein the spray dots of the coating liquid are shifted in the circumferential direction of the roll and overlap to form a line. The rotation speed corresponding to the outer diameter of the roll is calculated so that the speeds match, and when one rotation is completed, the dot at the end of the wire composed of the dots of the coating liquid becomes the dot at the end of the wire before one rotation. The running speed of the printer head in the roll surface length direction is calculated from the rotation speed of the roll, the length of the element wire formed by the dots of the coating liquid, and the overlap size of one dot so that the spiral shape is shifted and overlapped. Rotating the roll at the calculated rotation speed, and running the printer head at the calculated running speed while spraying the coating liquid from the printer head to form a uniform coating film on the roll. A method of forming a uniform coating film on the outer peripheral surface of a roll having various sizes. 2. A two-dimensional table supporting an ink jet type printer head is moved closer to a roll supported at both ends by chuck rotating means to move the printer head closer to a proper ejection gap with respect to the roll, or an appropriate ejection gap. When the approaching movement of the two-dimensional table is stopped just before the minute distance, the spray dots of the coating liquid are shifted in the circumferential direction of the roll and overlap to form a line. The rotation speed of the roll is calculated based on the outer diameter of the roll so that the speeds match, and the rolls, both ends of which are supported by the chuck rotating means, are driven to rotate at the rotation speed. , So that the set of dots that overlap with each other is spirally displaced by approximately one pitch in the roll circumferential direction and one dot at the end partially overlaps, The two-dimensional table is scanned in the roll surface length direction from the calculated rotation speed of the roll, the width of the spiral coating line formed by the dots, and the overlap dimension of the spiral coating line formed by the dots and the coating line. The speed is calculated and the two-dimensional table supporting the ink jet type printer head is scanned in the roll surface length direction at the calculated scanning speed in the roll surface length direction. When a negative image consisting of a uniform coating film is formed on the roll by spraying the coating liquid from the printer head while holding the printer head, and the printer head is brought closer to the roll by a small distance that becomes an appropriate spray gap, , And eject the coating liquid from the printer head while keeping the proper ejection gap closer to the roll. Wherein the forming a uniform coating film on the roll, the size to form a uniform coating film on the outer peripheral surface of the various rolls Te. 3. An ink jet type printer head and a gap sensor are arranged side by side and supported on a two-dimensional table, and the two-dimensional table is moved closer to a roll supported at both ends by chuck rotating means, and a gap between the roll and the roller is determined by the gap sensor. When the gap between the printer head and the roll is detected through precise measurement, the approach movement of the two-dimensional table is stopped when the gap approaches a value slightly larger than the proper ejection gap, and then the roll is driven to rotate. In addition, by scanning the printer head in the direction of the roll surface length of the roll, the printer head is spirally scanned relative to the roll, and the printer head is further brought closer to the roll to maintain an appropriate ejection gap to eject the coating liquid. And spray the coating liquid from the printer head to evenly coat the roll. Forming a cloth film,
A method of forming a uniform coating film on the outer peripheral surface of rolls of various sizes. 4. An ink jet type printer head is supported on a two-dimensional table so as to be finely movable in the diameter direction of the roll, and before the injection of the coating liquid is started, the eccentricity and whirling of the roll are measured and data is input to the controller. And performing an operation to correct the eccentricity and whirling of the roll by vibrating the micro-vibration device in the controller,
3. The printer head according to claim 1, wherein the printer head is held at an appropriate ejection gap with respect to the roll by vibrating the micro-vibration device corresponding to the eccentricity and whirling of the roll. The method for forming a uniform coating film on an outer peripheral surface of a roll having various sizes according to claim 1. 5. A printer head is supported on a Y table provided on a two-dimensional table and movable slightly in the diameter direction of a roll, and the Y table is shifted to a position closer to the roll to eject a coating liquid from the printer head. When cleaning the nozzle surface of the printer head during ejection, stop the movement of the two-dimensional table and retract the Y table to separate the printer head from the roll and operate the cleaner device provided on the two-dimensional table. Cleaning the nozzle surface of the printer head, and thereafter shifting the Y table to the whole body position and restarting the injection, wherein the jetting is restarted. A method for forming a uniform coating film on the outer peripheral surface of a roll having various sizes as described. 6. A printer head is provided on a two-dimensional table. The printer head is supported on a Y table which can be slightly moved in the diameter direction of a roll, and a gap sensor is arranged on the printer head and supported on the two-dimensional table. Approaching the roll that is supported at both ends and driven by rotation, precisely measure the gap with the roll by the gap sensor, and approach the printer head so that the gap to the roll is slightly larger than the proper ejection gap. When the movement of the two-dimensional table is stopped, the eccentricity and whirling of the roll are measured by a gap sensor prior to the start of the application liquid spraying, and the controller stores the data and determines the true diameter of the roll. Calculated and based on this, the printing is performed from the outer diameter of the roll and the line forming speed. The rotational speed of the roll is calculated so that the peripheral speed of the roll matches the required line forming speed of the coating liquid ejected from the head, and further, when the rotational speed of the roll and the coating liquid ejected from the printer head form a line. From the line width of the coating liquid and the overlap dimension of the line,
Calculate the running speed of the printer head in the roll surface direction,
Next, the two-dimensional table is reciprocated along the roll to detect the position and length of both ends of the roll by the gap sensor, and then the roll is rotated at the rotation speed and minutely corresponding to the eccentricity and whirling of the roll. By vibrating the vibrating device, the printer head at the standby position before the start of the ejection is further brought closer to the roll to maintain an appropriate ejection gap, and the printer head travels in the roll surface length direction at the traveling speed to move the printer head. While scanning in the required spiral relative to the roll, the coating liquid is sprayed from the printer head in accordance with the negative image data to form a negative image of the etching resist having a uniform film thickness on the roll, When cleaning the nozzle surface of the printer head on the way, stop the movement of the two-dimensional table and
By retracting the table, the printer head is separated from the roll, and the cleaner device provided on the two-dimensional table is operated to clean the nozzle surface of the printer head. Thereafter, the Y table is shifted to the whole body position to eject the ink. A method for forming a uniform coating film on the outer peripheral surface of a roll having various sizes, characterized by restarting.