JP2009006297A - Coating apparatus and method of manufacturing optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus capable of preventing a coating defect caused by an ejecting defect of an inkjet head with a simple configuration in coating using a line type, and to provide a method of manufacturing an optical film using the same. <P>SOLUTION: The coating apparatus includes a plurality of inkjet heads arranged in rows corresponding to a coating width in the width direction of a support medium being continuously transported and coating the support medium by ejecting liquid droplets of a coating liquid, a not ejecting head detecting part detecting an inkjet head ejecting no liquid droplets, and an auxiliary head having at least one inkjet head capable of positioning in the width direction of the support medium in the vicinity of the inkjet head rows wherein coating is continued by switching the not ejecting head to the auxiliary head. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a coating apparatus that applies a coating liquid to a support using an inkjet head that ejects droplets of the coating liquid, and a manufacturing method for manufacturing an optical film using the coating apparatus.

  Generally known are methods of forming an image using an ink jet method and forming a coated film including a patterned film on a support. An ink jet head used in an ink jet system has a plurality of ink ejection nozzles, and ejects droplets onto a support based on print data to form a desired image or coating film.

  In the ink ejection, for example, a piezo element or a heater is used to eject ink from the nozzles as fine droplets toward the support. For example, a piezo element as a piezoelectric element that deforms when a voltage is applied is attached to the nozzle, and the piezo element is deformed by applying a driving voltage to the piezo element, thereby compressing the ink flow path. Thus, ink is ejected from the nozzles.

  Here, ink is synonymous with coating liquid, and printing is synonymous with coating.

  As a method of forming the above-described image or coating film on a wide support, a serial type coating method in which the inkjet head is moved in the transport direction or the width direction of the support to perform coating, a plurality of supports in the width direction of the support A line-type coating method and the like in which an inkjet head is disposed to perform coating are known. In the line type, a plurality of inkjet heads corresponding to the coating width are arranged in the support width direction to perform coating.

  When forming a coating film on a long support that is continuously conveyed, the line-type coating method can eliminate scanning in the sub-scanning direction (support width direction) of the so-called inkjet head, and the injection of coating liquid. Position accuracy can be improved. Also, the coating speed can be increased.

  However, in the application by the ink jet method, a defect may occur in the coating film due to instability resulting from the application by ejecting minute application droplets from a fine nozzle. For example, nozzle contamination due to accumulation of usage time causes non-injection of the coating liquid, change in the injection angle, and an appropriate amount of the liquid, resulting in dispersion of the coating film thickness, so-called coating failure.

  When the application failure occurs, it is necessary to clean or replace the inkjet head. The cleaning or replacement during application is performed while the conveyance of the support is temporarily stopped or while the conveyance of the support is continued. Became enormous.

  A method of providing a fixed inkjet head for backup in consideration of a case where a defective nozzle is generated in the inkjet head in a line-type color printer using the fixed inkjet head, for problems such as non-injection of the inkjet head. It is disclosed (for example, see Patent Document 1).

In addition, a standby inkjet head of the same type as the main ejection inkjet head is made to stand by on the outer side in the support width direction downstream of the application position of the main ejection inkjet head, and the main ejection inkjet head It is disclosed that when the printer breaks down, it is immediately switched to a spare inkjet head (see, for example, Patent Document 2).
JP 2003-118149 A JP 2004-313895 A

  In Patent Document 1, the same inkjet head as a regular inkjet head corresponding to the coating width is provided as a spare. For this reason, even when the number of defective nozzles is one nozzle while using a regular inkjet head, a spare inkjet head corresponding to the coating width is used. In addition, there is a problem that the apparatus goes down when a defective nozzle is generated during use of the spare ink jet head. In addition, since the ink jet head corresponding to the coating width is used as a preliminary ink jet head, there is a problem that the apparatus size is large and the apparatus price is high.

  In Patent Document 2, since the preliminary inkjet head is waiting outside the support, adjustment (maintenance) of the preliminary inkjet head can be performed while waiting, and loss due to stoppage of the coating apparatus due to failure of the inkjet head can be reduced. it can. However, the number of spare inkjet heads is the same as the number of main ejection inkjet heads, and there is a problem that the apparatus size such as a moving mechanism to the application position is large and the apparatus price is high.

  The present invention has been made in view of the above situation, and in the application using the above-described line type, a coating apparatus capable of preventing a coating defect due to a defective ejection of an inkjet head with a simple configuration and an optical film using the coating apparatus. It aims at providing the manufacturing method of.

The above object is achieved by the following configurations and methods.
1. A plurality of inkjet heads arranged in a row corresponding to the coating width in the width direction of the support to be continuously conveyed, and ejecting liquid droplets of the coating liquid to coat the support
A non-ejecting head detection unit that detects the inkjet head that does not eject the droplet when the droplet is ejected from the inkjet head;
A coating apparatus comprising: a preliminary head having one or more inkjet heads that can be positioned in a width direction of the support in the vicinity of the row of the inkjet heads.
2. 2. The coating apparatus according to 1, wherein the plurality of inkjet heads are arranged in two rows in a staggered manner in the conveyance direction of the support.
3. 3. The coating apparatus according to 1 or 2, comprising a plurality of the preliminary heads.
4). 4. The apparatus according to claim 1, wherein the preliminary head is moved to a position in a support width direction of the inkjet head that does not eject the liquid droplets detected by the non-ejecting head detection unit. 5. Coating device.
5). The coating apparatus according to any one of claims 1 to 4, wherein the preliminary head is arranged in the vicinity of the downstream side of the row of the inkjet heads in the support transport direction.
6). 6. The spare head according to any one of claims 1 to 5, wherein the spare head stands by at a standby position outside the support in the width direction, and undergoes liquid flow, temperature adjustment, and flushing, and stands by in a usable state. Coating device.
7). The spare head is placed on a standby stage arranged outside in the support body width direction and stands by, and movement of the spare head in the support body width direction is performed by a linear motor. The coating apparatus according to any one of the above.
8). 8. The coating apparatus according to claim 7, wherein the preliminary stage mounts a plurality of the preliminary heads, and the preliminary heads can be rotated in the preliminary stage.
9. The non-ejection head detection unit detects the inkjet head that does not eject the liquid droplets by detecting an internal pressure of a supply path that supplies a coating liquid to the inkjet head. 2. The coating apparatus according to item 1.
10. The non-ejecting head detection unit does not eject the droplets by detecting the presence or absence of the ejection of the droplets from the inkjet head with a laser sensor disposed between the nozzle surface of the inkjet head and the support. The coating apparatus according to any one of 1 to 9, wherein the inkjet head is detected.
11. A method for producing an optical film using the coating apparatus according to any one of 11.1 to 10,
By detecting the length in the transport direction of the support from the position where the non-ejection of the liquid droplet occurred in the ink jet head to the position where the liquid droplet ejection ink jet head was switched to the preliminary head, The failure information is transmitted to the next step.

  As described above, in a coating apparatus that performs coating by arranging a plurality of inkjet heads corresponding to the coating width in the support width direction, even if an ejection failure of the inkjet head occurs, the coating is performed without stopping the support. Application failure can be recovered with a simple configuration while continuing. Moreover, since adjustment of the inkjet head which comprises a reserve head can be performed during application | coating, the injection defect of a reserve head can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a schematic diagram illustrating a configuration of a line-type coating apparatus 1. FIG. 2 is a partial perspective view of the vicinity of the head unit 30.

  The long support 10 wound in a roll shape is fed out in the direction of the arrow X from the unwinding roll 10A by a driving means (not shown) and conveyed.

  The long support 10 is wound around and supported by the back roll 20. The head unit 30 includes a plurality of inkjet heads 31 arranged in the support width direction corresponding to the application width. The coating liquid is ejected from the nozzles of the inkjet head 31 toward the support 10, and the coating liquid is applied to the support 10.

  In the form shown in FIG. 1, the inkjet head 31 is disposed and applied at a position where the support 10 after the support 10 passes through the back roll 20 is linearly conveyed in the conveyance direction. 20 may be applied. FIG. 14 shows an arrangement example when coating is performed on the back roll 20. The inkjet head 31 is disposed at a position facing the back roll 20 with the support 10 interposed therebetween. The liquid droplets are ejected in the direction of the substantially central axis of the back roll 20 and applied to the support 10. In the form shown in FIG. 14, the gap between the support 10 and the inkjet head 31 can be easily maintained stably.

  Since the coating width (injection width) that can be ejected by one inkjet head 31 is narrower than the outer dimensions of the inkjet head 31, the plurality of inkjet heads 31 are arranged so that they can be coated without any gaps. In this embodiment, as shown in FIG. 2, a plurality of inkjet heads corresponding to the coating width are arranged in two rows in a staggered manner in the support width direction. FIG. 3 shows the relationship among the outer shape, ejection width, and staggered arrangement of the inkjet head 31. The number of inkjet heads 31 and the number of rows in a staggered arrangement are appropriately set according to the ejection width, coating width, and the like of the inkjet head 31, and are not limited to the example of FIG.

  The spare head 50 (50a to 50h) has one or more inkjet heads 31 and is arranged in the vicinity of the downstream side in the transport direction of the support 10 in the row of the inkjet heads 31 of the head unit 30, and the width direction of the support 10 Wait at the outer standby position. It is preferable that a plurality of spare heads 50 are provided in order to cope with a case where a plurality of non-ejecting inkjet heads 31 are generated.

  Hereinafter, an inkjet head that does not eject droplets is also referred to as a non-ejection head.

  The standby stage 60 (60a, 60b) is disposed at the standby position, and the standby head 50 in the standby state is placed thereon. In the present embodiment, as shown in FIG. 2, two preliminary stages 60a and 60b are arranged on both outer sides of the support 10, and four preliminary heads 50a to 50d and 50e to 50h are mounted on each preliminary stage. Placed. Each spare head 50 includes one inkjet head 31.

  The preliminary stage 60 is provided with a head cleaning mechanism (not shown). The spare head 50 is adjusted by liquid passing, temperature adjustment and flushing by the cleaning mechanism at the standby position, and stands by in a usable state. As a result, even if the preliminary head 50 is not ejected due to clogging or the like, the function can be quickly recovered. The spare head 50 is placed so as to be able to rotate, so that the standby position can be changed in the spare stage 60. For example, the spare heads 50a to 50d are placed in the spare stage 60a so that the standby position can be changed. Thereby, the spare head 50 in which non-injection has occurred can be immediately replaced with a normal spare head 50. The number of spare heads 50 and spare stages 60 is not limited to the present embodiment.

  The spare head 50 is supported by a linear motion mechanism (not shown) so as to be movable in the width direction of the support 10 (in the Z1 and Z2 axis directions in FIG. 2). The linear motion mechanism preferably uses a linear motor. Thereby, the vibration at the time of a movement can be reduced and the influence which it has on the droplet during application | coating can be reduced. In addition, positioning accuracy during movement can be increased.

  The spare head 50 is moved by the linear motion mechanism to the position of the non-ejecting head that does not eject the droplets detected by the non-ejecting head detection unit (see FIGS. 5 and 6). Inject a drop. By arranging the spare head 50 in the vicinity of the downstream side in the transport direction of the support 10 in the row of the inkjet heads 31, it is possible to reduce the length of the poorly applied portion of the support 10 due to the non-injection of the inkjet head 31. it can.

  FIG. 4 is a schematic view showing a coating solution feeding pipe. The coating liquid is supplied from the pressure adjustment mechanism 40 that adjusts the back pressure of the coating liquid of the inkjet head 31 to each inkjet head 31 via a plurality of liquid feeding pipes 43 that are supply paths. Application liquid supply to the pressure adjusting mechanism 40 is performed by a liquid supply pump P disposed in the middle of a supply pipe 49 from a storage tank 48 that stores the application liquid. The liquid feeding valve 45 supplies and stops the coating liquid. The drain valve 46 is used when discharging a part of the coating liquid to the drain tank 47 in order to discharge bubbles and the like in the process of filling the inkjet head 31 with the coating liquid.

  The support 10 on which the coating film is formed is dried by the drying unit 100 and wound around the winding roll 10B.

  5 and 6 are schematic diagrams illustrating examples of the non-ejecting head detection unit.

  FIG. 5 shows the non-injection head detection unit 200 that detects the non-injection head by detecting the internal pressure of the liquid supply pipe 43 that supplies the coating liquid to the inkjet head 31. A pressure gauge PG arranged in the immediate vicinity of the ink jet head 31 detects an internal pressure change at the time of injection of the liquid feeding pipe, and when an internal pressure change occurs, it is determined that the corresponding ink jet head 31 has an abnormal injection. The internal pressure of the liquid supply pipe 43 of the ink jet head 31 in which non-injection has occurred increases.

  FIG. 6 shows a non-ejecting head that does not eject the liquid droplets by detecting the presence or absence of liquid droplet ejection from the ink jet head 31 with a laser sensor disposed between the support 10 and the nozzle surface of the ink jet head 31. The non-injection head detection part 300 which performs is shown. The laser light emitting unit 301 emits a laser beam LB between the support 10 and the nozzle surface of the inkjet head 31, and the light receiving unit 302 receives the laser beam LB.

  The laser light emitting unit 301 and the light receiving unit 302 are arranged at an angle so that the laser beam LB is not parallel to the nozzle row, and move and scan in the direction of the arrow XS. As a result, when a droplet is ejected from a certain nozzle and the laser beam LB is blocked, the nozzle is normal, and if it is not blocked, it can be determined that the nozzle is a non-ejecting nozzle.

  Next, the operation of the spare head when a non-injection head occurs will be described.

  FIG. 7 is a plan view showing a state before use of the spare head 50 (50a to 50h) as seen from the inkjet head 31 in the direction of the support 10. As described above, the spare heads 50a to 50d are placed on the spare stage 60a, and the spare heads 50e to 50h are placed on the spare stage 60b in a ready-to-use state, adjusted through liquid flow, temperature adjustment and flushing. .

  The spare head 50 is moved in the width direction of the support 10 by a linear motor (not shown). In the present embodiment, the linear motors are arranged in two rows of the Z1 axis and the Z2 axis, and the spare head 50 is configured to be movable in two rows.

  FIG. 8 is a diagram when two non-injection heads are generated. When the non-injection head detection unit 200 or 300 detects the non-injection heads 31a and 31b, the spare head 50f is moved on the Z1 axis and positioned at a position corresponding to the non-injection head 31a. Similarly, the spare head 50c is moved on the Z2 axis and positioned at a position corresponding to the non-injection head 31b. Next, the liquid feeding to the non-injection heads 31a and 31b is stopped and the liquid is fed to the spare heads 50f and 50c, and instead the injection is started.

  FIG. 9 is a diagram when two non-ejecting heads are generated from the state shown in FIG. The spare head 50e is moved on the Z2 axis and positioned at a position corresponding to the non-injection head 31c. Similarly, the spare head 50d is moved on the Z1 axis and positioned at a position corresponding to the non-injection head 31d. Next, the injection of the non-injection heads 31c and 31d is stopped, and the spare heads 50e and 50d start injection instead.

  FIG. 10 is a diagram showing a response when non-injection occurs in the spare head 50f in the state shown in FIG. The spare head 50f returns to the spare stage 60b, the spare head 50 on the spare stage is rotated, and the spare head 50g moves on the Z1 axis. Next, the spare head 50g is moved on the Z1 axis, positioned at a position corresponding to the non-injection head 31a, and starts injection. The non-injection preliminary head 50f that has returned to the preliminary stage 60b is restored to the injection function. Further, the spare head 50 that replaces the spare head 50f may be a spare head 50h instead of the spare head 50g.

  As described above, when non-ejection occurs in the inkjet head 31, the non-ejecting head can be quickly switched to the spare head, and the length of the poorly applied portion of the support 10 can be reduced. Further, even if non-ejection due to clogging or the like occurs in the spare head 50, the function can be quickly recovered.

  11 and 12 are schematic plan views showing examples of other installation arrangements other than the staggered arrangement of the ink jet heads 31.

  In FIG. 11, the inkjet head 31 has the nozzle face of each inkjet head and the support 10 parallel to each other, maintaining a constant interval, and the center of the nozzle openings arranged in the width direction orthogonal to the transport direction of the support 10. The angle formed by the line connecting the two and the conveying direction of the coated body is arranged at a predetermined angle (θ). In addition, in order to eliminate an uncoated portion between adjacent heads, the rear end portion (downstream in the transport direction of the support 10) and the front end portion (upstream in the transport direction of the support 10) of each head are arranged so as to overlap each other. ing. FIG. 12 shows a modified example of the staggered arrangement. The specification of the arrangement conforms to the case of the staggered arrangement described above. Also in the arrangements shown in FIGS. 11 and 12, correspondence to the non-injection head is performed using the spare head 50 as in the above-described embodiment.

  FIG. 13 is a diagram showing another form of operation using the spare head 50 when a non-ejecting head is generated. The arrangement of the inkjet head 31 will be described by taking the arrangement shown in FIG. 11 as an example. When the non-ejecting head 31n is generated in the ink jet head 31 arranged in the head unit 30b, the head unit 30b stops the injection, and the head replacement position of the preliminary stage 60e (in the arrow Y direction by a head unit moving mechanism (not shown)) ( 13). At the head replacement position, the non-injection head 31n is moved to the preliminary stage 60f by a head replacement mechanism (not shown). Next, the spare head 50n placed on the spare stage 60e is moved and placed by the head replacement mechanism to the position where the non-injection head 31n of the head unit 30b was located. Thereafter, the head unit 30b returns to the application position and resumes injection. Further, the head unit 30b may be fixed, and the preliminary stages 60e and 60f may be moved to the position of the non-injection head 31n to replace the head.

  In the form shown in FIG. 13, by removing the non-injection head 31n from the application position, the recovery function of the injection function can be performed outside the application position, and the number of spare heads can be reduced.

  In the production of the optical film using the coating apparatus, the support from the position where the non-ejection of the liquid droplet occurs in the ink jet head to the position where the liquid droplet ejection ink jet head is switched to the spare head and the liquid droplet ejection is started. It is preferable to detect the length in the conveying direction as failure information and transmit the failure information to the next process. As a result, the defective application portion can be eliminated in the next step, and the processing (processing) in the next step can be limited to only the normal application portion, thereby reducing the loss of processing (processing) time in the next step. it can.

It is a schematic diagram which shows the outline of a structure of the coating device which concerns on this invention. It is a fragmentary perspective view of the vicinity of a head unit. It is a figure which shows the relationship between the external shape of an inkjet head, an injection width, and zigzag arrangement. It is the schematic which shows the liquid feeding piping of a coating liquid. It is the schematic which shows the example of a non-injection head detection part. It is the schematic which shows the example of a non-injection head detection part. It is a top view which shows the state before use of a reserve head. It is an operation | movement figure of a reserve head when two non-injection heads arise. It is an operation | movement figure of a reserve head when four non-injection heads arise. It is a figure which shows a response | compatibility when non-injection arises in a reserve head. It is a schematic plan view which shows the example of another installation arrangement | sequence of an inkjet head. It is a schematic plan view which shows the example of another installation arrangement | sequence of an inkjet head. It is a figure which shows another form of the reserve head when a non-injection head arises. It is a figure which shows the example of arrangement | positioning of an inkjet head and a reserve head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating device 10 Support body 20 Back roll 30 Head unit 31 Inkjet head 40 Pressure adjustment mechanism 43 Liquid supply piping 50 Spare head 60 Spare stage 100 Drying part 200, 300 Non-injection head detection part 301 Laser light emission part 302 Light receiving part LB Laser beam PG pressure gauge

Claims (11)

A plurality of inkjet heads arranged in a row corresponding to the coating width in the width direction of the support to be continuously conveyed, and ejecting liquid droplets of the coating liquid to coat the support
A non-ejecting head detection unit that detects the inkjet head that does not eject the droplet when the droplet is ejected from the inkjet head;
A coating apparatus comprising: a preliminary head having one or more inkjet heads that can be positioned in a width direction of the support in the vicinity of the row of the inkjet heads. The coating apparatus according to claim 1, wherein the plurality of inkjet heads are arranged in two rows in a zigzag manner in a conveyance direction of the support. The coating apparatus according to claim 1, wherein a plurality of the preliminary heads are provided. 4. The spare head is moved to a position in the support width direction of the inkjet head that does not eject the liquid droplets detected by the non-ejection head detection unit. 5. The coating apparatus as described. 5. The coating apparatus according to claim 1, wherein the preliminary head is disposed in the vicinity of the downstream side of the row of the inkjet heads in the support conveyance direction. 6. 6. The spare head stands by at a stand-by position outside the support in the width direction, undergoes liquid flow, temperature adjustment, and flushing, and stands by in a usable state. The coating apparatus as described in. 2. The standby head is placed on a standby stage arranged outside in the support body width direction and stands by, and movement of the backup head in the support body width direction is performed by a linear motor. 7. The coating apparatus according to any one of items 6 to 6. The coating apparatus according to claim 7, wherein the preliminary stage mounts a plurality of the preliminary heads, and the preliminary heads can be rotated in the preliminary stage. 9. The non-ejecting head detection unit detects the inkjet head that does not eject the liquid droplets by detecting an internal pressure of a supply path that supplies a coating liquid to the inkjet head. The coating apparatus according to any one of the above. The non-ejecting head detection unit does not eject the droplets by detecting the presence or absence of the ejection of the droplets from the inkjet head with a laser sensor disposed between the nozzle surface of the inkjet head and the support. The coating apparatus according to any one of claims 1 to 9, wherein the inkjet head is detected. A method for producing an optical film using the coating apparatus according to any one of claims 1 to 10,
By detecting the length in the transport direction of the support from the position where the non-ejection of the liquid droplet occurs in the ink jet head to the position where the ink jet head of the liquid droplet ejection is switched to the spare head, the failure information is detected. The failure information is transmitted to the next step.

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