JP2012148476A - Printing apparatus and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing apparatus which are capable of eliminating even a complicated printing misalignment, and a printing method.SOLUTION: A plurality of heating units 40 and a plurality of cooling units 45 are alternately arranged in a peripheral direction in the inner circumferential surface of a plate cylinder 14. The heating units 40 and the cooling units 45 are extended in a direction parallel to the rotary shaft 14a of the plate cylinder 14. A printing plate PL on which a stripe-like pattern to be transferred to a substrate is formed is attached to the outer circumferential surface of the plate cylinder 14. The printing plate PL attached to the plate cylinder 14 is controlled in temperature, to be expanded and contracted in each area in the peripheral direction of the plate cylinder 14 by the plurality of heating units 40 and the plurality of cooling units 45. Consequently, even when the complicated printing misalignment occurs, the temperature of the pattern area of the printing plate PL is controlled to different temperature for each area to correct a total pitch and eliminate the printing misalignment.

Description

  The present invention relates to a printing apparatus and a printing method for transferring a light emitting material of organic electroluminescence (organic EL) from a printing plate mounted on an outer peripheral surface of a plate cylinder to a substrate.

  In recent years, organic EL light-emitting materials that are being developed include polymer materials using polymer molecules and low-molecular materials using other molecules. In any of the light emitting materials, it is difficult to form a pattern using a photolithography method due to restrictions on the base film. For this reason, vapor deposition using a metal mask has been put to practical use for low molecular weight materials, and pattern formation by various printing methods has been attempted for high molecular weight materials.

  In the printing method using a relief plate, a light emitting material as ink is applied to the projections of the printing plate on which a pattern is formed, and the pattern is transferred to a transfer target (usually a transparent glass substrate). As the printing plate, a resin plate (for example, a polyester-based resin plate) is used from the viewpoint of printing on a glass substrate which is a brittle material.

  On the other hand, organic EL applications are roughly classified into lighting applications and display applications. For lighting applications, it is sufficient to form a solid film of relatively large size, but in the case of display applications, it is necessary to coat each luminescent material of RGB with high definition with a line width of tens to hundreds of microns, The positional accuracy is required to be ± 10 microns or less. For example, when R ink is separately applied as a light emitting material of an organic EL to a display pattern in which RGB (red, green, blue) are sequentially arranged in a stripe shape, for R on one end formed in a printing region of a glass substrate It is necessary to match the total pitch from the cell to the R cell on the other end side with the total pitch of the R ink printing result by the printing plate with an accuracy of ± 10 microns or less. If the total pitch of the printed result is too long, the both ends of the printing area of the glass substrate will protrude, and if it is too short, color mixing with the adjacent G ink and B ink will occur, causing uneven emission. It becomes.

  However, when a light emitting material is applied to a glass substrate for display using a relief printing method, the resin material printing plate has a large linear expansion coefficient, and the size of the plate easily changes due to the influence of temperature and humidity. is there. In particular, if the size of the pattern area to be printed is large, it is extremely difficult to finish the total pitch of the printing area on the glass substrate side and the total pitch of the printing result with an accuracy of ± 10 microns or less each time.

  For this reason, if color mixing occurs without matching the total pitch of the printing results to the printing area of the glass substrate, it is necessary to repeat the trial and error until the two match, which increases costs and There was a problem of prolonged plate-making days. As a technique for solving this, it is conceivable to adjust the total pitch of the printing plate by adjusting the temperature. For example, Patent Document 1 discloses that a temperature control unit is provided on a plate surface plate on which a plate plate of an offset printing machine is placed, and the plate plate is expanded and contracted by heat to increase the accuracy of the printing pitch. Patent Document 2 discloses that a temperature setting unit is provided in any one of the printing plate placing unit, the substrate placing unit, and the blanket, and the printing pitch is adjusted by temperature control to increase printing accuracy.

JP-A-4-279349 JP 2005-246904 A

  However, when the organic EL light-emitting material is actually applied to the printing area of the glass substrate using the relief printing method, a more complicated printing deviation occurs than the total pitch of the printing result is simply too large or too small. Often occurs. Specifically, the total pitch of the printing result may vary between the printing start side and the printing end side. This is due to the deformation of the printing plate as a result of printing while pressing the printing plate against the substrate in order to suppress the influence of minute variations in the thickness of the printing plate that occurred during plate making. is there. And when complicated printing misalignment arises, it is difficult to eliminate this with the techniques disclosed in Patent Documents 1 and 2.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a printing apparatus and a printing method capable of eliminating even complicated printing misalignment.

  In order to solve the above problems, the invention of claim 1 is a printing apparatus comprising: a stage for holding a substrate in which a printing area is defined in a horizontal posture; and a printing plate having a predetermined pattern of protrusions formed on a surface thereof. A hollow cylindrical plate cylinder mounted on the outer peripheral surface, a supply mechanism for supplying a printing material to the printing plate mounted on the plate cylinder, and the printing plate supplied with the printing material to the substrate A transfer mechanism that transfers the predetermined pattern to the printing region by pressing, the transfer mechanism rotating a plate cylinder about a rotation axis along a horizontal direction, and the substrate. A horizontal movement mechanism for relatively moving the stage to be held and the plate cylinder along a horizontal direction perpendicular to the rotation axis, and along the circumferential direction on the inner peripheral surface of the plate cylinder, Extending in a direction parallel to the rotation axis And providing a plurality of temperature adjustment units for performing temperature adjustment of the plate cylinder.

  According to a second aspect of the present invention, in the printing apparatus according to the first aspect of the invention, the plurality of temperature adjustment units include a heating unit that heats the plate cylinder and a cooling unit that cools the plate cylinder. It is characterized by that.

  According to a third aspect of the present invention, in the printing apparatus according to the second aspect of the present invention, the heating unit and the cooling unit are alternately arranged along the circumferential direction on the inner peripheral surface of the plate cylinder. Features.

  According to a fourth aspect of the present invention, in the printing apparatus according to any one of the first to third aspects, the width of the predetermined pattern of the printing plate parallel to the rotation axis coincides with the width of the printing area. As described above, it further comprises control means for individually controlling the temperatures of the plurality of temperature adjustment units.

  Further, the invention of claim 5 is the printing apparatus according to any one of claims 1 to 4, wherein the predetermined pattern is a stripe pattern, and the stripe forming direction of the convex portion of the printing plate is the stripe pattern. The printing plate is mounted on the plate cylinder so as to coincide with the circumferential direction of the plate cylinder.

  According to a sixth aspect of the present invention, in the printing method, the substrate holding step for holding the substrate in which the printing area is defined in a horizontal position, and the printing plate having a predetermined pattern of protrusions formed on the surface of the hollow cylinder A printing plate mounting step for mounting on the outer peripheral surface of the plate cylinder having a shape; a supplying step for supplying a printing material to the printing plate mounted on the plate cylinder; and the rotation axis along the horizontal direction of the plate cylinder. While rotating, the printing plate supplied with the printing material is pressed against the substrate by relatively moving the substrate and the plate cylinder along a horizontal direction perpendicular to the rotation axis. The transfer step of transferring the predetermined pattern to the printing region, and a plurality of temperature adjustment units provided on the inner peripheral surface of the plate cylinder along the circumferential direction and extending in a direction parallel to the rotation axis. A temperature adjustment process for adjusting the temperature of the plate cylinder And wherein the Rukoto.

  According to a seventh aspect of the invention, in the printing method according to the sixth aspect of the invention, the plurality of temperature adjustment units include a heating unit that heats the plate cylinder and a cooling unit that cools the plate cylinder. It is characterized by that.

  According to an eighth aspect of the present invention, in the printing method according to the seventh aspect of the invention, the heating unit and the cooling unit are arranged alternately along the circumferential direction on the inner peripheral surface of the plate cylinder. Features.

  The invention of claim 9 is the printing method according to any one of claims 6 to 8, wherein, in the temperature adjustment step, the width of the predetermined pattern of the printing plate parallel to the rotation axis is the width. The temperature of the plurality of temperature adjustment units is individually adjusted so as to coincide with the width of the print region.

  The invention according to claim 10 is the printing method according to any one of claims 6 to 9, wherein the predetermined pattern is a striped pattern, and the printing plate mounting step includes a projection of the printing plate. The printing plate is mounted on the plate cylinder so that the stripe forming direction of the portion coincides with the circumferential direction of the plate cylinder.

  According to the first to fifth aspects of the present invention, the temperature of the plate cylinder is adjusted by extending in the direction parallel to the rotation axis of the plate cylinder along the inner circumferential surface of the plate cylinder on which the printing plate is mounted. Since there are multiple temperature adjustment units that perform printing, the temperature can be individually adjusted and expanded for each area along the plate cylinder circumferential direction of the printing plate, and even complicated printing misalignments can be eliminated It becomes.

  In particular, according to the invention of claim 2, since the temperature adjustment unit includes a heating unit for heating the plate cylinder and a cooling unit for cooling the plate cylinder, the printing plate is stretched in response to a complicated printing misalignment. Or it can be shrunk.

  According to the inventions of claims 6 to 10, the inner surface of the plate cylinder on which the printing plate is mounted is provided along the circumferential direction so as to extend in a direction parallel to the rotation axis of the plate cylinder. Since the temperature of the plate cylinder is adjusted by multiple temperature adjustment units, the temperature can be individually adjusted and expanded for each area along the plate cylinder circumferential direction of the printing plate, eliminating complex printing misalignments. It becomes possible to do.

  In particular, according to the invention of claim 7, since the temperature adjustment unit includes a heating unit for heating the plate cylinder and a cooling unit for cooling the plate cylinder, the printing plate is stretched in response to a complicated printing misalignment. Or it can be shrunk.

1 is a perspective view of an entire printing apparatus according to the present invention. FIG. 3 is a side view illustrating a main configuration of the printing apparatus. It is sectional drawing which cut | disconnected the printing cylinder by the plane perpendicular | vertical to a rotating shaft. It is a figure which shows the arrangement configuration of a heating unit and a cooling unit. It is a figure which shows the hardware constitutions of a control part. 3 is a flowchart showing a processing procedure in the printing apparatus of FIG. 1. FIG. 2 is a plan view of a substrate to be printed by the printing apparatus of FIG. 1. It is a top view of a printing plate. It is a figure which shows an example of the printing misalignment discovered by test printing. It is a figure for demonstrating the total pitch adjustment of the printing plate in 1st Embodiment. It is a figure which shows the other example of the printing misalignment discovered by trial printing. It is a figure for demonstrating the total pitch adjustment of the printing plate in 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
First, an example of the configuration of a printing apparatus according to the present invention will be described. FIG. 1 is a perspective view of the entire printing apparatus 10 according to the present invention. FIG. 2 is a side view showing the main configuration of the printing apparatus 10. In FIG. 1 and the subsequent drawings, an XYZ orthogonal coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane is attached as necessary to clarify the directional relationship. Further, in FIG. 1 and the subsequent drawings, the dimensions and numbers of the respective parts are exaggerated or simplified as necessary for easy understanding.

  The printing apparatus 10 performs a printing process for forming a pattern of an organic EL element by transferring an organic EL light emitting material as an ink to the substrate W. The printing apparatus 10 includes a base 20, a stage 22, a plate cylinder 14, an ink supply mechanism 13, and a transfer mechanism 50 as main components. In addition, the printing apparatus 10 includes a control unit 90 that controls each operation mechanism of the apparatus to execute a printing process.

  As shown in FIG. 1, a pair of linear motion guides 32 and a linear motor 31 disposed between the linear motion guides 32 are provided on the base 20. The linear motion guide 32 and the linear motor 31 are arranged such that their longitudinal directions are along a horizontal direction (Y direction) perpendicular to the rotation shaft 14 a of the plate cylinder 14. An alignment table 51 is connected to the linear motion guide 32 and the linear motor 31, and a stage 22 that holds the substrate W in a horizontal posture is disposed on the alignment table 51. For this reason, the alignment table 51 is linearly moved along the horizontal direction (Y direction) perpendicular to the rotation shaft 14 a of the plate cylinder 14 together with the stage 22 under the drive of the linear motor 31. Further, the alignment table 51 incorporates a position adjusting mechanism for adjusting the position of the stage 22. The position adjustment mechanism slides the stage 22 with respect to the alignment table 51 in the X direction and the Y direction, and rotates it in the θ direction.

  Support side plates 24 are fixed to the left and right side surfaces of the base 20. A pair of guide members 25 are arranged on the support side plate 24 along the vertical direction (Z direction). The lifting table 21 is guided by these four guide members 25 and can be lifted and lowered. Further, a slit nozzle 11, an ink supply roller 12, a plate cylinder 14 and a plate cylinder motor 15 are mounted on the lifting table 21. These elements move up and down together with the lifting table 21 by driving the lifting motor 26.

  The plate cylinder 14 is a roller having a hollow cylindrical shape, and is disposed so as to be rotatable around a rotation shaft 14a extending along the X direction. The plate cylinder 14 is rotated by a plate cylinder motor 15 about a rotation shaft 14a along the horizontal direction. The plate cylinder 14 can be rotated clockwise and counterclockwise on the paper surface of FIG. 2, but is rotated clockwise by the plate cylinder motor 15 during the printing process. A resin printing plate PL (in this embodiment, a relief plate) is mounted on the outer peripheral surface of the plate cylinder 14. The resin printing plate PL is formed of a resin such as polyester, for example. Both ends of the printing plate PL are fixed on the outer peripheral surface of the plate cylinder 14 by a clamp mechanism (not shown).

  FIG. 3 is a cross-sectional view of the plate cylinder 14 cut along a plane (YZ plane) perpendicular to the rotation axis 14a. A plurality of temperature adjustment units (temperature adjustment units) are provided along the circumferential direction on the inner peripheral surface of the plate cylinder 14 having a hollow cylindrical shape. The plurality of temperature control units include a heating unit 40 that heats the plate cylinder 14 and a cooling unit 45 that cools the plate cylinder 14. That is, the “temperature control unit” is a conceptual term including the heating unit 40 and the cooling unit 45, and is a general term for these.

  FIG. 4 is a diagram showing an arrangement configuration of the heating unit 40 and the cooling unit 45, and the inside of the plate cylinder 14 of FIG. The heating unit 40 and the cooling unit 45 are rod-shaped temperature control units that extend in a direction (X direction) parallel to the rotation shaft 14 a of the plate cylinder 14. The lengths in the X direction of the heating unit 40 and the cooling unit 45 are at least longer than the width of the printing plate PL mounted on the plate cylinder 14. As the heating unit 40, for example, a heater such as a resistance heating element that generates heat when energized can be used. Moreover, as the cooling unit 45, a Peltier element using the Peltier effect or the like can be used.

  The plate cylinder 14 is provided with a plurality of heating units 40 and a plurality of cooling units 45. As shown in FIGS. 3 and 4, the heating units 40 and the cooling units 45 are alternately arranged on the inner peripheral surface of the plate cylinder 14 along the circumferential direction. The arrangement pitch of the heating unit 40 and the cooling unit 45 (the arrangement interval between the adjacent heating unit 40 and the cooling unit 45) is not particularly limited, but may be, for example, about 20 mm to 100 mm. Moreover, in FIG. 3, although the cross-sectional shape of the heating unit 40 and the cooling unit 45 is made into the column shape, this shape is not specifically limited, For example, other shapes, such as a square pole shape, may be sufficient.

  Returning to FIG. 2, the ink supply mechanism 13 supplies the organic EL polymer light-emitting material as ink (printing material) to the printing plate PL mounted on the plate cylinder 14. The ink supply mechanism 13 includes a slit nozzle 11 and an ink supply roller 12. The ink supply roller 12 is disposed parallel to the plate cylinder 14 (that is, along the X direction). The slit nozzle 11 has a slit extending in the rotation axis direction (X direction) of the ink supply roller 12, and discharges an organic EL polymer light emitting material as ink onto the surface of the ink supply roller 12. The interval between the slit nozzle 11 and the surface of the ink supply roller 12 and the interval between the surface of the ink supply roller 12 and the surface of the printing plate PL on the plate cylinder 14 can be adjusted by an adjustment mechanism (not shown).

  In the printing apparatus 10, ink is supplied from the slit nozzle 11 to the surface of the ink supply roller 12 that rotates, and a thin film of a luminescent material is formed on the surface of the ink supply roller 12. Then, when both the ink supply roller 12 and the plate cylinder 14 are rotated, the ink is transferred from the ink supply roller 12 to the pattern of the printing plate PL mounted on the plate cylinder 14 to form a pattern of the light emitting material. Further, while the stage 22 holding the substrate W is moved at a constant speed along the Y direction by the linear motor 31, the plate cylinder 14 is rotated by the plate cylinder motor 15, and the printing plate PL on which the ink is placed is moved with respect to the substrate W. The pattern of the luminescent material is transferred from the printing plate PL to the substrate W by pressing. That is, the transfer mechanism 50 is configured by the plate cylinder motor 15 that rotates the plate cylinder 14 and the linear motor 31 that moves the stage 22.

  FIG. 5 is a diagram illustrating a hardware configuration of the control unit 90. The configuration of the control unit 90 as hardware is the same as that of a general computer. That is, the control unit 90 stores a CPU 91 that performs various arithmetic processes, a ROM 92 that is a read-only memory that stores basic programs, a RAM 93 that is a readable / writable memory that stores various information, control software, data, and the like. The magnetic disk 94 to be placed is connected to the bus line 99.

  The bus line 99 includes a plate cylinder motor 15 that rotates the plate cylinder 14, a lift motor 26 that moves the lift table 21 up and down, a linear motor 31 that moves the stage 22 in a linear motion, a heating unit 40, a cooling unit 45, and ink supply. Elements such as the mechanism 13 are electrically connected. The plurality of heating units 40 and the plurality of cooling units 45 provided in the plate cylinder 14 are individually controlled by the control unit 90. Further, the bus line 99 may be connected to a display for displaying various information, a keyboard for receiving input of commands and parameters, and a disk drive for reading a recording medium such as a DVD.

  Next, processing operations in the printing apparatus 10 having the above-described configuration will be described. FIG. 6 is a flowchart illustrating a processing procedure in the printing apparatus 10. First, the operator of the printing apparatus 10 mounts the printing plate PL on the outer peripheral surface of the plate cylinder 14 (step S1). Further, the operator of the printing apparatus 10 holds the substrate W on the stage 22 (step S2). Note that the order of step S1 and step S2 may be reversed.

  The substrate W is held on the stage 22 in a horizontal posture. FIG. 7 is a plan view of the substrate W to be printed by the printing apparatus 10. The substrate W of this embodiment is a glass substrate for organic EL display applications. On the substrate W, a print area PA is defined in advance before the printing process. In the print area PA, a plurality of cells are formed in a stripe shape (stripe shape). Each of the plurality of cells corresponds to one of RGB. The substrate W is held on the stage 22 so that the stripe formation direction (longitudinal direction of the stripe) of the print area PA is along the Y direction.

  FIG. 8 is a plan view of the printing plate PL mounted on the plate cylinder 14. The printing plate PL is a resin relief plate for transferring an organic EL light emitting material to the substrate W, and has a striped pattern region PR formed on the surface thereof. That is, a convex portion having a predetermined pattern is formed on the surface of the printing plate PL. This pattern region PR corresponds to the print region PA of the substrate W, and the light emitting material is transferred to one cell of the print region PA by one convex portion forming a stripe of the pattern region PR. The printing plate PL is mounted on the plate cylinder 14 so that the stripe forming direction of the convex portions of the pattern region PR coincides with the circumferential direction of the plate cylinder 14.

  Next, the organic EL polymer light emitting material is supplied as ink to the printing plate PL mounted on the plate cylinder 14 by the ink supply mechanism 13 (step S3). Specifically, the ink discharged from the slit nozzle 11 is transferred to the convex portion of the pattern region PR of the printing plate PL by the ink supply roller 12. Then, trial printing on the substrate W is executed (step S4). That is, while the substrate W held on the stage 22 is linearly moved along a horizontal direction perpendicular to the rotation axis 14a of the plate cylinder 14, the printing cylinder 14 is rotated around the rotation axis 14a, and printing is supplied with ink. By bringing the plate PL into contact with the substrate W, the ink is transferred from the pattern area PR to the printing area PA.

  When the ink is transferred from the printing plate PL to the substrate W, the printing plate PL is slightly pressed against the substrate W of the stage 22. Specifically, the control unit 90 controls the elevating motor 26 to raise and lower the elevating table 21 so that the surface of the printing plate PL at the lower end of the plate cylinder 14 is pressed against the substrate W of the stage 22. The height position of the plate cylinder 14 is adjusted. The reason why the printing process is performed by pressing the printing plate PL against the substrate W in this way is to eliminate the influence of minute variations in the thickness of the printing plate PL generated during plate making. That is, if the printing process is performed at the height position of the plate cylinder 14 where the surface of the printing plate PL is just in contact with the surface of the substrate W, printing unevenness occurs due to variations in the thickness of the printing plate PL. The printing process is executed while pressing the printing plate PL against the substrate W at the height position of the lower plate cylinder 14.

  When the resin printing plate PL is pressed against the glass substrate W held on the stage 22, the printing plate PL is deformed at the contact point. When the printing plate PL is deformed, a printing misalignment occurs. In addition, printing misalignment also occurs when the initial state of the pattern area PR of the printing plate PL is not aligned with the printing area PA.

  FIG. 9 is a diagram illustrating an example of printing misalignment determined by trial printing. If the normal printing process is performed, the printing result PK in which the pattern area PR of the printing plate PL is transferred to the surface of the substrate W and the printing area PA of the substrate W coincide with each other. However, when a printing misalignment occurs due to the deformation of the printing plate PL as described above, the printing result PK to which the pattern region PR is transferred and the printing region PA do not match as shown in FIG. In FIG. 9, the degree of printing misalignment is exaggerated for easy understanding (the same applies to FIG. 11 described later).

  In the first embodiment, the total pitch of the printing results PK is shorter than the total pitch of the printing area PA of the substrate W. The total pitch of the printing result PK is a distance from one end side line to the other end side line of the stripe pattern of the printing result PK, and is a width of the printing result PK perpendicular to the stripe forming direction. On the other hand, the total pitch of the printing area PA is a distance from one end side cell to the other end side cell of the printing area PA, and is a width of the printing area PA perpendicular to the stripe formation direction. As shown in FIG. 9, when the total pitch of the printing results PK is shorter than the total pitch of the printing area PA, there is a possibility that color mixing of RGB ink occurs and light emission unevenness occurs.

  For this reason, the total pitch of the printing plate PL is adjusted by a plurality of temperature control units provided in the plate cylinder 14 (step S5). The total pitch of the printing plate PL is synonymous with the total pitch of the pattern region PR of the printing plate PL, and is the width of the pattern region PR perpendicular to the stripe formation direction. The total pitch of the printing result PK also changes in conjunction with the change in the total pitch of the printing plate PL.

  FIG. 10 is a diagram for explaining the total pitch adjustment of the printing plate PL in the first embodiment. FIG. 10 shows the printing plate PL mounted on the plate cylinder 14 and the heating unit 40 and the cooling unit 45 provided on the inner peripheral surface of the plate cylinder 14 in the region where the printing plate PL is mounted ( The body of the plate cylinder 14 is not shown). In the figure, for the sake of easy understanding and convenience of explanation, four heating units 40 and four cooling units 45 are provided below the printing plate PL. However, the number is not limited to this number. Instead, an appropriate value can be taken according to the size of the printing plate PL and the arrangement interval between the heating unit 40 and the cooling unit 45.

  In the first embodiment, the total pitch of the printing results PK is evenly shorter than the total pitch of the printing area PA. That is, the difference between the total pitch of the printing results PK and the total pitch of the printing area PA is constant at any position in the stripe formation direction. Therefore, under the control of the control unit 90, the four heating units 40 provided below the printing plate PL are heated by the same rising temperature. The heated heating unit 40 directly heats the plate cylinder 14, and the printing plate PL is heated by heat conduction from the plate cylinder 14. In the heated printing plate PL, thermal expansion according to the increased temperature occurs. As a result, the total pitch of the pattern area PR of the printing plate PL is extended, and the total pitch of the printing result PK matches the total pitch of the printing area PA of the substrate W, thereby correcting the printing misalignment.

  In FIG. 9, printing misalignment occurs at both ends (upper and lower ends of the drawing) of the print result PK, but the misprinting in the stripe forming direction does not cause problems such as color mixing. You can leave it alone. In the first embodiment, since the total pitch of the printing results PK is too short, it is necessary to thermally expand the printing plate PL, and no special control is performed on the cooling unit 45 below the printing plate PL. .

The rising temperature of the four heating units 40 may be calculated from the difference between the total pitch of the printing results PK and the total pitch of the printing area PA. More specifically, the temperature at which the printing plate PL should be heated is calculated based on the difference between the total pitch of the printing result PK and the total pitch of the printing area PA and the linear expansion coefficient (linear expansion coefficient) of the printing plate PL, Based on the calculation result, the rising temperature of the heating unit 40 necessary for raising the temperature of the printing plate PL is calculated. For example, it is assumed that the total pitch of the printing area PA of the substrate W is 500 mm, and the total pitch of the print result PK of the trial printing is 40 μm shorter than that. In this case, the linear expansion coefficient of PET (polyethylene terephthalate), which is the base material of the printing plate PL, is 6 × 10 ⁻⁵ / ° C., and the resin of the concavo-convex portion formed thereon has the same dimensions as the base PET. Since it expands and contracts, printing deviation can be corrected by raising the temperature of the printing plate PL by about 1.3 ° C. Then, the temperature rise of the heating unit 40 is calculated so that the printing plate PL is heated by about 1.3 ° C. and stored in the storage unit (RAM 93 or magnetic disk 94) of the control unit 90. The control unit 90 performs control so that the four heating units 40 are heated by the increased temperature based on the set value of the increased temperature stored in the storage unit.

  In this way, the heating unit 40 heats the printing plate PL via the plate cylinder 14 to cause thermal expansion of the printing plate PL, so that the total pitch of the pattern area PR is the total pitch of the printing area PA of the substrate W. Is stretched to match. As a result, the total pitch of the printing result PK and the total pitch of the printing area PA coincide with each other, and the printing deviation is eliminated. In the first embodiment, since all the four heating units 40 provided below the printing plate PL are heated by the same rising temperature, they are uniformly distributed over the entire area along the stripe forming direction of the printing plate PL. By heating, the total pitch of the pattern region PR is uniformly extended.

  After the total pitch adjustment of the printing plate PL by temperature control is completed, the substrate W that has undergone trial printing is removed from the stage 22 and a new substrate W is held on the stage 22 (step S6). This new substrate W is the same as the test print substrate W held on the stage 22 in step S2 (see FIG. 7), and is a glass substrate for organic EL display use in which the print area PA is defined. is there. However, the new substrate W to be held on the stage 22 in step S6 is a substrate to be actually subjected to printing processing.

  Then, the luminescent material is again supplied as ink from the ink supply mechanism 13 to the printing plate PL, and the printing drum PL is brought into contact with the substrate W by rotating the plate cylinder 14 while moving the stage 22 linearly. Is executed (step S7). While the actual printing process is being performed, the temperature of the printing plate PL is continuously increased by the heating unit 40 as described above. As a result, in the actual printing process, the total pitch of the printing result PK in which the pattern area PR of the printing plate PL is transferred to the surface of the substrate W matches the total pitch of the printing area PA of the substrate W, which is recognized by the trial printing. The printing misalignment is eliminated.

Second Embodiment
Next, a second embodiment of the present invention will be described. The configuration of the printing apparatus 10 according to the second embodiment and the procedure of the processing operation are the same as those in the first embodiment (see FIGS. 1 to 6). The second embodiment differs from the first embodiment in the mode of printing misalignment found in the trial printing in step S4 and the temperature control mode of the printing plate PL for correcting it.

  FIG. 11 is a diagram illustrating printing misalignment in the second embodiment. When the printing process is executed while pressing the resin printing plate PL from the rotating plate cylinder 14 that rotates with respect to the substrate W held on the stage 22, as shown in FIG. 11, the printing start side (upper side in FIG. 11). In many cases, the trapezoidal printing result PK has a width that gradually increases from the printing end to the printing end (the lower side in FIG. 11). This is because the pressed printing plate PL is deformed so as to be spread from the printing start side toward the printing end side.

  In the second embodiment, the total pitch of the printing results PK on the printing start side is shorter than the total pitch of the printing area PA of the substrate W. On the contrary, on the printing end side, the total pitch of the printing results PK is longer than the total pitch of the printing area PA. For this reason, also in the second embodiment, the total printing plate PL is provided by a plurality of temperature control units provided in the plate cylinder 14 so that the total pitch of the printing results PK matches the total pitch of the printing area PA of the substrate W. Adjust the pitch.

  FIG. 12 is a diagram for explaining the total pitch adjustment of the printing plate PL in the second embodiment. In the drawing, for convenience of explanation, the shape of the printing result PK is drawn by reflecting the shape of the pattern region PR. That is, the shape of the pattern region PR considering the change due to pressing is drawn. In the second embodiment, the difference between the total pitch of the print results PK and the total pitch of the print area PA varies along the stripe formation direction. For this reason, the control unit 90 performs different temperature control for each of the plurality of heating units 40 and cooling units 45 provided below the printing plate PL.

  Specifically, the heating unit 40a provided below the pattern area PR corresponding to the printing start side where the total pitch of the printing results PK is the shortest than the total pitch of the printing area PA has a relatively large rising temperature. Temperature. Conversely, the cooling unit 45c provided below the pattern region PR corresponding to the printing end side where the total pitch of the printing results PK is longer than the total pitch of the printing region PA is lowered at a relatively large lowering temperature. To do.

  The heating unit 40b provided below the pattern region PR corresponding to the position where the total pitch of the printing results PK is slightly shorter than the total pitch of the printing region PA is heated at a temperature that is lower than that of the heating unit 40a. . Further, the temperature of the heating unit 40c provided below the pattern region PR corresponding to the position where the total pitch of the printing results PK is longer than the total pitch of the printing region PA is not changed.

  Similarly, the cooling unit 45b provided below the pattern region PR corresponding to the position where the total pitch of the printing results PK is slightly longer than the total pitch of the printing region PA is lower than the cooling unit 45c. Lower the temperature. Further, the temperature of the cooling unit 45a provided below the pattern area PR corresponding to the position where the total pitch of the printing results PK is shorter than the total pitch of the printing area PA is not changed.

  The heating unit 40 (the heating unit 40a and the heating unit 40b) whose temperature has been raised heats the printing plate PL via the plate cylinder 14 in accordance with the degree of the rising temperature. The cooled cooling unit 45 (cooling unit 45c and cooling unit 45b) cools the printing plate PL via the plate cylinder 14 according to the degree of the lowered temperature. In a part of the heated printing plate PL, thermal expansion corresponding to the increased temperature occurs, and the pattern region PR is expanded. On the contrary, in a part of the cooled printing plate PL, the pattern region PR is contracted according to the lowered temperature. As a result, the total pitch of the pattern area PR of the printing plate PL is adjusted, and the total pitch of the printing result PK matches the total pitch of the printing area PA of the substrate W, whereby the printing misalignment is corrected.

  As for the rising temperature of the heating unit 40a and the heating unit 40b and the falling temperature of the cooling unit 45c and the cooling unit 45b, as in the first embodiment, the difference between the total pitch of the printing results PK and the total pitch of the printing area PA. It may be calculated from the linear expansion coefficient of the printing plate PL. Then, the calculation result is stored in the storage unit of the control unit 90. The control unit 90 performs control so that the heating unit 40a and the heating unit 40b are heated by the rising temperature based on the set value of the rising temperature stored in the storage unit, and based on the setting value of the falling temperature. The cooling unit 45c and the cooling unit 45b are controlled so as to drop the temperature by the lowered temperature.

  In this way, the printing plate PL is expanded and contracted so that the total pitch of the pattern area PR matches the total pitch of the printing area PA of the substrate W, and the total pitch of the printing result PK and the printing area PA The print pitch is eliminated by matching the total pitch. In the second embodiment, since the deviation between the total pitch of the printing results PK and the total pitch of the printing area PA is not constant, the total pitch is individually corrected for each area of the pattern area PR of the printing plate PL.

<Advantages of printing technology according to the present invention>
In the printing technique according to the present invention, a plurality of temperature control units (heating unit 40 and cooling unit 45) are provided along the circumferential direction of the plate cylinder 14. By individually controlling the temperatures of the plurality of heating units 40 and cooling units 45, the printing plate PL mounted on the plate cylinder 14 is temperature-controlled and expanded for each area along the circumferential direction of the plate cylinder 14. Can do.

  For this reason, as in the first embodiment, when the difference between the total pitch of the printing results PK and the total pitch of the printing area PA is constant, the pattern area PR of the printing plate PL is arranged in the entire area along the stripe formation direction. The total pitch of the pattern region PR can be expanded and contracted uniformly by controlling the temperature uniformly. On the other hand, when the deviation between the total pitch of the printing results PK and the total pitch of the printing area PA is not constant as in the second embodiment, the pattern area PR of the printing plate PL is divided into areas along the stripe formation direction. The expansion and contraction of the total pitch of the pattern region PR can be individually adjusted by adjusting the temperature to different temperatures. In any case, the pattern of the printing plate PL is set so that the total pitch of the pattern region PR of the printing plate PL matches the total pitch of the printing region PA of the substrate W, that is, parallel to the rotation axis 14a of the plate cylinder 14. The control unit 90 individually controls the temperatures of the plurality of temperature control units so that the width of the print area PA matches the width of the print area PA.

  Therefore, regardless of the mode of deviation between the total pitch of the printing results PK and the total pitch of the printing area PA, the temperature of the printing plate PL is controlled by a plurality of temperature control units provided along the circumferential direction of the plate cylinder 14. Thus, the total pitch of the printing results PK can be matched with the total pitch of the printing area PA of the substrate W. In this way, according to the printing technique according to the present invention, even complicated printing misalignment can be eliminated.

<Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in each of the above embodiments, both the heating unit 40 and the cooling unit 45 are provided as a plurality of temperature control units in the plate cylinder 14, but only the heating unit 40 or only the cooling unit 45 is provided. Also good. When only the heating unit 40 is provided in the plate cylinder 14 as a temperature control unit, the pattern region PR of the printing plate PL is formed smaller in advance at the time of plate making. Then, the printing result PK to which the pattern region PR is transferred is surely smaller than the printing region PA of the substrate W, and the total pitch of the pattern region PR is made to coincide with the total pitch of the printing region PA only by heating by the heating unit 40. Can do. On the contrary, when only the cooling unit 45 is provided as the temperature control unit, the pattern area PR of the printing plate PL may be formed larger in advance at the time of plate making.

  In each of the above embodiments, the plate cylinder 14 is provided with a plurality of rod-shaped temperature control units. However, the shape of the temperature control unit is not limited to a rod shape, for example, a long sheet shape or the like. It may be. In the case of a sheet-like temperature control unit, since the size of the temperature control region in charge is defined by the width (the length along the circumferential direction of the plate cylinder 14), the pattern region PR is finely divided for each area. If the temperature is controlled, it is preferable to narrow the width. However, when the temperature of the entire pattern region PR of the printing plate PL is uniformly controlled as in the first embodiment, the temperature may be controlled by a single sheet-like temperature control unit.

  Further, as the heating unit 40 and the cooling unit 45, piping for flowing constant temperature water at a predetermined temperature may be disposed on the inner peripheral surface of the plate cylinder 14. Furthermore, you may make it comprise both the heating unit 40 and the cooling unit 45 by a Peltier device. In this case, by reversing the polarity of the current passed through the Peltier element, one Peltier element functions as the heating unit 40 and the other Peltier element functions as the cooling unit 45. In this way, the arrangement configuration of the heating unit 40 and the cooling unit 45 can be freely changed simply by controlling the polarity of the current.

  In the first embodiment, since the total pitch of the printing results PK is shorter than the total pitch of the printing area PA, the printing plate PL is heated using only the heating unit 40. When the total pitch of the PK is longer, the printing plate PL may be cooled only by the four cooling units 45 provided below the printing plate PL. That is, the printing plate PL may be temperature-controlled so that the total pitch of the pattern area PR matches the total pitch of the printing area PA.

  In each of the above embodiments, the substrate W held on the stage 22 is linearly moved with respect to the plate cylinder 14. However, the plate cylinder 14 rotates while the stage 22 holding the substrate W is stationary. The ink may be transferred from the pattern area PR to the printing area PA by linear movement along the horizontal direction (Y direction) perpendicular to the axis 14a. In other words, the stage 22 holding the substrate W and the plate cylinder 14 may be moved relative to each other along a horizontal direction perpendicular to the rotation shaft 14a.

  Further, as a material of the printing plate 17, the printing technique according to the present invention can be applied as long as it is a material that is deformed by a normal printing pressure.

  Further, in each of the above embodiments, an example of pattern printing on a glass substrate using an organic EL light emitting material as a coating liquid has been described. The present invention can be applied to the manufacture of substrates such as glass substrates for liquid crystals, flexible liquid crystal substrates, and electronic paper.

  The present invention can be suitably applied to a printing technique in which a printing material is transferred from a printing plate to a substrate, and in particular, printing must be performed by accurately matching the total pitch of the printing plate pattern with the total pitch of the printing area of the substrate. Suitable for printing organic EL and printing on color filters.

DESCRIPTION OF SYMBOLS 10 Printing apparatus 13 Ink supply mechanism 14 Plate cylinder 15 Plate cylinder motor 22 Stage 26 Lifting motor 31 Linear motor 32 Linear motion guide 40 Heating unit 45 Cooling unit 50 Transfer mechanism 90 Control part PA Printing area PK Printing result PL Printing plate PR Pattern area W substrate

Claims (10)

A stage for holding a substrate having a printing area in a horizontal position;
A hollow cylindrical plate cylinder on the outer peripheral surface of which a printing plate having a predetermined pattern of protrusions formed on the surface is mounted;
A supply mechanism for supplying a printing material to the printing plate mounted on the plate cylinder;
A transfer mechanism for transferring the predetermined pattern to the printing region by pressing the printing plate supplied with the printing material against the substrate;
With
The transfer mechanism is
A rotation mechanism that rotates the plate cylinder around a rotation axis along a horizontal direction;
A horizontal movement mechanism for relatively moving the stage holding the substrate and the plate cylinder along a horizontal direction perpendicular to the rotation axis;
Have
A printing apparatus comprising: a plurality of temperature adjustment units that extend in a circumferential direction along a circumferential direction of the plate cylinder in a direction parallel to the rotation axis and adjust the temperature of the plate cylinder. The printing apparatus according to claim 1.
The plurality of temperature adjustment units are:
A heating unit for heating the plate cylinder;
A cooling unit for cooling the plate cylinder;
A printing apparatus comprising: The printing apparatus according to claim 2, wherein
The printing apparatus, wherein the heating unit and the cooling unit are alternately arranged along the circumferential direction on an inner peripheral surface of the plate cylinder. The printing apparatus according to any one of claims 1 to 3,
The printing apparatus further comprising control means for individually controlling temperatures of the plurality of temperature adjustment units so that a width of the predetermined pattern of the printing plate parallel to the rotation axis coincides with a width of the printing area. apparatus. The printing apparatus according to any one of claims 1 to 4,
The predetermined pattern is a stripe pattern,
The printing apparatus, wherein the printing plate is mounted on the plate cylinder so that a stripe forming direction of convex portions of the printing plate coincides with a circumferential direction of the plate cylinder. A substrate holding step for holding the substrate in which the printing area is defined in a horizontal posture;
A printing plate mounting step for mounting a printing plate having a predetermined pattern of protrusions on the outer surface of a hollow cylindrical plate cylinder;
Supplying a printing material to the printing plate mounted on the plate cylinder;
The printing material is supplied by moving the substrate and the plate cylinder relatively along a horizontal direction perpendicular to the rotation axis while rotating the plate cylinder about a rotation axis along the horizontal direction. A transfer step of pressing the printed plate against the substrate and transferring the predetermined pattern to the printing area;
A temperature adjustment step for adjusting the temperature of the plate cylinder by a plurality of temperature adjustment units provided on the inner peripheral surface of the plate cylinder along the circumferential direction and extending in a direction parallel to the rotation axis;
A printing method comprising: The printing method according to claim 6.
The plurality of temperature adjustment units are:
A heating unit for heating the plate cylinder;
A cooling unit for cooling the plate cylinder;
A printing method comprising: The printing method according to claim 7, wherein
The printing method, wherein the heating unit and the cooling unit are alternately arranged along the circumferential direction on the inner peripheral surface of the plate cylinder. In the printing method in any one of Claims 6-8,
In the temperature adjustment step, the temperature of the plurality of temperature adjustment units is individually adjusted so that a width of the predetermined pattern of the printing plate parallel to the rotation axis coincides with a width of the printing area. How to print. In the printing method in any one of Claims 6-9,
The predetermined pattern is a stripe pattern,
In the printing plate mounting step, the printing plate is mounted on the plate cylinder so that a stripe forming direction of convex portions of the printing plate coincides with a circumferential direction of the plate cylinder.

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