JP5493908B2 - Printing machine, light emitting layer forming method, and organic light emitting device - Google Patents

Description

  The present invention relates to a printing machine that prints ink on a substrate, and more particularly to a printing machine that simultaneously prints different types of ink on a substrate. Moreover, this invention relates to the method of forming the light emitting layer in the light emitting element layer of an organic light emitting device using the said printing machine. The present invention also relates to an organic light emitting device having a light emitting layer formed by the printing machine.

  As a method for accurately forming a polymer thin film on a substrate, a method is known in which an ink in which a polymer organic material is dissolved in a solvent is printed on the substrate using a printing machine. For example, Patent Document 1 proposes a method of forming a light emitting layer constituting an organic light emitting device by gravure offset printing.

  Generally, the light emitting layer of the organic light emitting device includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer. In the organic light emitting device, it is possible to express any color by providing the light emitting layers of a plurality of colors in this way. When forming the light emitting layer of a plurality of colors by printing, a plurality of types of inks corresponding to the respective colors are printed on the substrate.

  As a method of printing multiple types of ink on the substrate, the ink is sequentially printed on the substrate one by one while shifting the substrate surface plate on which the substrate is placed in a direction (width direction) perpendicular to the printing direction. The method is known. In this case, first, one type of ink is printed on the substrate, and then the substrate surface plate is shifted by a predetermined distance in the width direction. Thereafter, other types of ink are printed on the substrate. In this case, printing is performed a number of times corresponding to the type of ink.

  In addition, a method for printing a plurality of types of ink on a substrate more efficiently has been proposed. For example, in Patent Document 1, first, a gravure plate having a plurality of striped cells arranged in the width direction is filled with red ink, green ink and blue ink, respectively, and then each color ink is placed on a transfer roll. Has been proposed, and then, the ink of each color on the transfer roll is transferred onto the substrate. In this case, each color ink is transferred onto the substrate by one printing.

JP 2006-318850 A Japanese Patent Application Laid-Open No. 60-20426

  In the printing method of Patent Document 2, a plurality of striped cells of a gravure plate are arranged in the width direction. For this reason, when filling each cell with ink of each color, it is considered that different types of inks are mixed. When such a color mixture occurs, the characteristics regarding the color purity of each layer formed from the ink deteriorate.

  The present invention has been made in consideration of such points, and provides a printing machine capable of efficiently printing a plurality of colors of ink on a substrate without causing color mixing of the inks. With the goal.

  The present invention relates to a printing machine for printing ink on a substrate, a frame, a plate-shaped ink plate disposed on the frame and having cells on the upper surface thereof, and an ink for supplying ink to the upper surface of the ink plate. A supply unit, a doctor that fills the cell with ink on the upper surface of the ink plate, and a frame that is allowed to run on the frame, abuts the ink plate and receives the ink in the cell, A transfer roll for transferring ink onto a substrate, and the ink plate is partitioned into a plurality of regions each having a length corresponding to a circumferential length of the transfer roll along a running direction of the transfer roll. In each area, different types of ink are supplied from the ink supply unit, and the cells in one area of the ink plate are shifted in the width direction relative to the cells in the other area. The region located downstream of the most upstream region among the regions of it is printing machine, characterized in that the recess it from the cell and overlap in the width direction of the upstream region is provided.

  The present invention relates to a printing machine for printing ink on a substrate, which is a roll-shaped ink plate having an cell on its outer peripheral surface, and an ink supply unit for supplying ink to the outer peripheral surface of the ink plate And a doctor that fills the cell with ink on the outer peripheral surface of the ink plate, and a transfer roll that contacts the ink plate and receives the ink in the cell, and transfers the ink onto the substrate, The ink plate is partitioned into a plurality of regions each having a length corresponding to the circumferential length of the transfer roll along the rotation direction of the ink plate, and different types of ink are supplied to each region from the ink supply unit. The cells in one area of the ink plate are shifted in the width direction with respect to the cells in the other area, and the areas on the downstream side of the most upstream area of each area of the ink plate , Upstream of it A printing machine, wherein a concave portion that overlaps the cell of the frequency in the width direction are provided.

  In the printing press of the present invention, an ink discharge hole may be provided on the downstream side of the cell in each region of the ink plate.

  In the printing machine of the present invention, a separate doctor may be provided in each region of the ink plate.

  In the printing press of the present invention, the ink plate may have a plurality of cells arranged in a stripe shape and filled with ink from an ink supply unit. In this case, preferably, the ratio b / a of the length b in the printing direction and the width a in the direction orthogonal to the printing direction in each cell is 0.6 or more, and the cell part length L and the non-cell part length S of each cell. The ratio L / S is in the range of 0.8 to 100, the cell part length L is in the range of 10 to 500 μm, the non-cell part length S is in the range of 2 to 500 μm, and the plate of each cell The depth is in the range of 20 to 200 μm.

  In the printing press of the present invention, the ink plate may have a plurality of cells that are arranged in a lattice shape and are filled with ink from an ink supply unit. In this case, preferably, the ratio b / a of the maximum length b in the printing direction and the maximum width a in the direction orthogonal to the printing direction in each cell is 0.6 or more, and the total cell area occupying the film formation site is The non-cell portion length S is in the range of 2 to 500 μm, and the plate depth of each cell is in the range of 20 to 200 μm.

  In the printing machine of the present invention, the transfer roll may include a blanket cylinder and a blanket provided integrally on the peripheral surface of the blanket cylinder. In this case, preferably, the blanket is made of a resin film having a surface tension of 35 dyne / cm or more.

  In the printing machine of the present invention, the thickness of the resin film is preferably in the range of 5 to 200 μm.

  In the printing machine of the present invention, a cushion layer may be interposed between the blanket cylinder and the blanket.

  In the printing press of the present invention, the transfer roll may include a blanket cylinder and a base material provided on the peripheral surface of the blanket cylinder. In this case, the ink filled in the cells of the ink plate is directly transferred onto the substrate of the transfer roll.

  The present invention provides a method for forming the light-emitting layer of an organic light-emitting device comprising the opposing electrodes and the light-emitting element layer provided between the electrodes and having at least a light-emitting layer, using the printing press described above. Supplying the ink containing a luminescent material to the ink plate, filling the ink plate with cells of the ink plate, allowing the transfer roll to receive the ink from the ink plate, and And a step of transferring ink onto a substrate.

  In the light emitting layer forming method of the present invention, the light emitting layers may be formed so as to be arranged at a predetermined pixel pitch in the width direction. In this case, the cells in one area of the ink plate are separated from the cells in other areas adjacent to the one area by the pixel pitch in the width direction.

  In the light emitting layer forming method of the present invention, in the step of supplying ink to the ink plate, the ink supplied to the cells in one region is the cells in one region and the upstream region adjacent to the one region. You may supply between cells.

  In the light emitting layer forming method of the present invention, the ink is composed of a solvent and a solid content dissolved in the solvent, and preferably has a viscosity (ink temperature 23 ° C.) at a shear rate of 100 / sec in the range of 5 to 200 cP. The solvent has a surface tension of 40 dyne / cm or less and a boiling point of 150 to 250 ° C.

  In the light emitting layer formation method of this invention, Preferably, content of the solid content in the said ink exists in the range of 1.5 to 4.0 weight%.

  The present invention includes a substrate, a first electrode layer formed in a desired pattern on the substrate, and a plurality of portions formed on the substrate and exposing a desired portion of the first electrode layer upward. An insulating layer having an opening, a light-emitting element layer having at least a light-emitting layer formed to cover the first electrode layer in the opening and run over the insulating layer on the periphery of the opening; A second electrode layer formed so as to be connected to the light emitting element layer located in the opening, and the light emitting layer of the light emitting element layer is formed by the above-described light emitting layer forming method. An organic light emitting device characterized by the following.

  In the organic light-emitting device of the present invention, preferably, a variation in thickness of a portion located in the opening of the light-emitting layer constituting the light-emitting element layer is 10% or less.

  In the organic light-emitting device of the present invention, the light-emitting element layer may be formed by laminating at least a hole injection layer / a light-emitting layer / an electron injection layer in this order.

  The organic light emitting device of the present invention may be a passive matrix type.

  The organic light emitting device of the present invention may be an active matrix type.

  The organic light-emitting device of the present invention may be an organic light-emitting poster provided with the opening having a maximum opening width of 10 mm or more in the insulating layer.

  The organic light emitting device of the present invention may include a color filter layer.

  The organic light emitting device of the present invention may include a color conversion phosphor layer between the color filter layer and the transparent electrode.

  In the organic light emitting device of the present invention, the light emitting element layer may emit light of a desired color including white, or may be a combination of light emission of a desired plurality of colors in a predetermined pattern.

  In the organic light emitting device of the present invention, the light emitting element layer may emit blue light. In this case, the color conversion phosphor layer includes a green conversion layer that converts blue light into green fluorescence and emits light, and a red conversion layer that converts blue light into red fluorescence and emits light.

  The organic light emitting device of the present invention forms the coating film for the light emitting layer within 1 minute after forming the coating film for the hole injection layer, and simultaneously drys these two layers in the range of 100 to 200 ° C. A hole injection layer and a light emitting layer formed in this manner may be provided.

According to the present invention, a printing machine that prints ink on a base material includes a frame, a plate-shaped ink plate that is arranged on the frame and has cells on the upper surface thereof, and an ink that supplies ink to the upper surface of the ink plate. A feeding unit, a doctor that fills the cell with ink on the top surface of the ink plate, and a frame that can run on the frame, are in contact with the ink plate to receive the ink in the cell, and on the substrate And a transfer roll for transferring ink. The ink plate is divided into a plurality of regions each having a length corresponding to the circumferential length of the transfer roll along the running direction of the transfer roll. Ink is supplied. The cells in one area of the ink plate are shifted in the width direction with respect to the cells in the other area. For this reason, each ink can be received by the transfer roll without mixing a plurality of colors of ink.
Further, in each region of the ink plate, a region on the downstream side of the most upstream region is provided with a recess in a portion overlapping with a cell in the upstream region in the width direction. This recess can prevent the ink received by the transfer roll in the upstream region from coming into contact with the downstream region. Thus, a plurality of types of ink received by the transfer roll can be transferred onto the substrate at one time while maintaining a desired thickness.

Further, according to the present invention, the printing machine for printing ink on the substrate is a roll-shaped ink plate, an ink plate having cells on its outer peripheral surface, and an ink for supplying ink to the outer peripheral surface of the ink plate A supply unit, a doctor that fills the cell with ink on the outer peripheral surface of the ink plate, and a transfer roll that contacts the ink plate to receive the ink in the cell and transfer the ink onto the substrate. . The ink plate is divided into a plurality of regions each having a length corresponding to the circumferential length of the transfer roll along the rotation direction of the ink plate. Ink is supplied. For this reason, each ink can be received by the transfer roll without mixing a plurality of colors of ink.
The cells in one area of the ink plate are shifted in the width direction with respect to the cells in the other area. Further, in each region of the ink plate, a region on the downstream side of the most upstream region is provided with a recess in a portion overlapping with a cell in the upstream region in the width direction. This recess can prevent the ink received by the transfer roll in the upstream region from coming into contact with the downstream region. Thus, a plurality of types of ink received by the transfer roll can be transferred onto the substrate at one time while maintaining a desired thickness.

  According to the invention, a method of forming an organic light emitting device including a light emitting element layer having at least a light emitting layer includes a step of forming a light emitting layer by the above described light emitting layer forming method. For this reason, a light emitting layer of a plurality of colors can be formed by one printing. For this reason, it is possible to form the light emitting layers of a plurality of colors in a shorter time and with higher accuracy than when the light emitting layers of the respective colors are sequentially formed by printing.

  According to the present invention, an organic light emitting device includes a base material, an insulating layer formed on the base material in a desired pattern, and having a plurality of openings that expose a desired portion of the first electrode layer, The first electrode layer in the opening is covered and formed on the insulating layer on the periphery of the opening, and is connected to the light emitting element layer having at least the light emitting layer and the light emitting element layer located in the desired opening. And a formed second electrode layer. Among these, the light emitting layer is formed by the above-described light emitting layer forming method. For this reason, the organic light emitting device provided with the light emitting layer formed accurately can be provided.

FIG. 1 is a side view showing a printing press according to an embodiment of the present invention. FIG. 2 is a plan view showing an ink plate according to the embodiment of the present invention. FIGS. 3A, 3B and 3C are plan views showing a ratio b / a of the width b in the printing direction of the cells of the ink plate and the width a in the direction perpendicular to the cell in the embodiment of the present invention. . FIG. 4 is a longitudinal sectional view showing a blanket in the embodiment of the present invention. FIG. 5 is a partial cross-sectional perspective view showing an organic light-emitting device according to an embodiment of the present invention. 6A to 6E are views showing a method for forming an organic light-emitting device according to an embodiment of the present invention. 7A and 7B are diagrams showing a printing machine in a comparative example. FIG. 8 is a diagram showing another embodiment of the printing machine according to the present invention. FIG. 9 is a diagram showing another embodiment of the printing machine according to the present invention. FIG. 10 is a diagram showing another embodiment of the printing machine according to the present invention. FIGS. 11A to 11D are views showing another embodiment of a method for forming an organic light emitting device according to the present invention. FIG. 12 is a view showing another embodiment of the gravure plate in the present invention. FIG. 13 is a view showing another embodiment of the gravure plate in the present invention. FIG. 14 is a diagram showing another embodiment of a gravure plate according to the present invention. FIG. 15 is a plan view showing another embodiment of the organic light-emitting device according to the present invention. 16 is a diagram showing a relationship between the light emitting layer and the opening of the insulating layer in the organic light emitting device shown in FIG. FIG. 17 is a perspective view showing another embodiment of the organic light-emitting device according to the present invention. 18 is a cross-sectional view taken along line AA of the organic light emitting device shown in FIG. FIG. 19 is a partial cross-sectional view showing another embodiment of the organic light-emitting device in the present invention. FIG. 20 is a partial cross-sectional view showing another embodiment of the organic light-emitting device in the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6. First, the entire printing press 10 will be described with reference to FIG.

〔Printer〕
As shown in FIG. 1, a printing press 10 includes a frame 5 and a plate-like gravure plate 1 (ink) that is arranged on the frame 5 and has a pattern portion 4 composed of a plurality of cells 2 (described later) on its upper surface. Plate), a base plate 6 placed on the frame 5 and on which a flat base plate 32 is placed, and the frame 5 provided on the frame 5 so as to be able to travel along the printing direction indicated by the arrow P on the frame 5. The transfer roll 24 is provided. As shown in FIG. 1, on the traveling direction side (right side in FIG. 1) of the transfer roll 24, an ink supply unit 7 that supplies ink 30 to the upper surface of the gravure plate 1, and ink supplied from the ink supply unit 7. A doctor 8 for filling 30 in the cell 2 of the pattern part 4 of the gravure plate 1 is provided. Further, as described later, the transfer roller 24, a blanket cylinder 25, the blanket 23 integrally provided on the peripheral surface of the blanket cylinder 25, and consists of, the circumference of the transfer roller 24 becomes t ₁ ing.

  In such a printer 10, when the transfer roll 24 comes into contact with the gravure plate 1, the ink 30 is received by the blanket 23 of the transfer roll 24 with a pattern corresponding to the pattern portion 4 of the gravure plate 1. The ink 30 received by the blanket 23 is then transferred onto the substrate 32. Thus, according to the printing machine 10 of the present embodiment, so-called gravure offset printing is performed by the combination of the gravure plate 1 and the transfer roll 24.

[Gravure version]
Next, the gravure plate 1 will be described in detail.
As shown in FIG. 1, the gravure plate 1 is divided into a plurality of regions (first region 15a, second region 15b, and third region 15c) along the traveling direction (printing direction P) of the transfer roll 24. Yes. Further, the lengths of the regions 15 a, 15 b and 15 c in the running direction of the transfer roll 24 are all the same as the circumferential length t ₁ of the transfer roll 24. Here, the design part in the first region 15a is the first design part 4a, the design part in the second region 15b is the second design part 4b, and the design part in the third region 15c is the third design part. It is part 4c.

As shown in FIG. 1, in the printing press 10, different types of ink 30 are supplied from the ink supply unit 7 to the regions 15 a, 15 b, and 15 c of the gravure plate 1. Specifically, as shown in FIG. 1, the red ink 30R is supplied from the ink supply unit 7a to the first region 15a, and the green ink 30G is supplied from the ink supply unit 7b to the second region 15b. Blue ink 30B is supplied to the region 15c from the ink supply unit 7c. The inks 30R, 30G, and 30B supplied to the regions 15a, 15b, and 15c are filled into the pattern portions 4a, 4b, and 4c of the regions 15a, 15b, and 15c by the doctor 8.
In this way, by supplying a plurality of types of ink 30 on one gravure plate 1, a plurality of types of ink 30 can be simultaneously printed on the substrate 32 as will be described later.

In the gravure plate 1, the pattern portion of one region is shifted in the width direction H (direction perpendicular to the printing direction P) with respect to the pattern portion of the other region. Specifically, as shown in FIG. 1, the first pattern portion 4a of the first region 15a, only _{t 2} in the widthwise direction with respect to the second pattern portion 4b of the second region 15b adjacent to the first region 15a It is off. Although not shown, similarly, a second pattern portion 4b of the second region 15b is shifted by _{t 2} in the widthwise direction with respect to the third pattern portion 4c of the third region 15c adjacent to the second region 15b. In this way, when the ink 30 is received by the transfer roll 24 by shifting the pattern portion of one region by t _{2 in the} width direction H with respect to the pattern portion of the other region, different types of inks are Mixing on the transfer roll 24 can be prevented.
As will be described later, when the light emitting layer 38 is formed on the transparent substrate 32 of the organic light emitting device 31 by the printing machine 10, the above-described dimension t ₂ is equal to the pixel pitch of the organic light emitting device 31.

Further, among the regions 15a, 15b, and 15c of the gravure plate 1, the second region 15b and the third region 15c, which are located downstream of the most upstream first region 15a, include the pattern portions of the regions upstream thereof. A concave portion 14 is provided in a portion overlapping in the width direction H.
Specifically, as shown in FIG. 1, the second region 15b is provided with a recess 14a at a portion overlapping the first pattern portion 4a of the first region 15a in the width direction H. In this case, the recess 14a can prevent the ink 30R received by the transfer roll 24 from the first pattern portion 4a from adhering to the second region 15b when the transfer roll 24 abuts on the second region 15b. It is formed with a size of about.
Similarly, as shown in FIG. 1, the third region 15c is provided with a recess 14b in a portion overlapping the first pattern portion 4a of the first region 15a in the width direction H, and the second region 15b A concave portion 14c is provided in a portion overlapping the two pattern portions 4b in the width direction H. As in the case of the concave portion 14a of the second region 15b, the concave portions 14b and 14c of the third region 15c prevent the inks 30R and 30G received by the transfer roll 24 from adhering to the third region 15c. It is formed with dimensions that can be done.
In this manner, by providing the recesses 14a, 14b, and 14c in the regions downstream of the most upstream region among the regions of the gravure plate 1, the gravure plate 1 is received by the transfer roll 24 from the pattern portion 4 in the upstream region. It is possible to prevent the attached ink 30 from adhering to the downstream region. As a result, the inks 30 of a plurality of colors received by the transfer roll 24 can be simultaneously transferred onto the base material 32 while maintaining a desired thickness.

  Further, as shown in FIG. 1, separate doctors 8 are provided in the respective regions 15 a, 15 b, 15 c of the gravure plate 1. Specifically, as shown in FIG. 1, a first doctor 8a is provided in the first region 15a to which the red ink 30R is supplied, and a second doctor 8b is provided in the second region 15b to which the green ink 30G is supplied. The third doctor 8c is provided in the third region 15c to which the blue ink 30B is supplied. By providing a separate doctor for each region in this way, it is possible to prevent different types of ink from being mixed while the ink 30 is being scraped by the doctor.

Further, as shown in FIG. 1, in each region 15a, 15b, 15c of the gravure plate 1, an ink discharge hole 9 is provided on the downstream side of each of the pattern portions 4a, 4b, 4c. Specifically, a first ink discharge hole 9a is provided on the downstream side of the pattern portion 4a in the first region 15a, and a second ink discharge hole 9b is provided on the downstream side of the pattern portion 4b in the second region 15b. A third ink discharge hole 9c is provided on the downstream side of the pattern portion 4c in the third region 15c. These ink discharge holes 9 a, 9 b, 9 c have a shape that is recessed below the upper surface of the gravure plate 1. For this reason, each ink discharge hole 9 a, 9 b, 9 c has a pattern on the gravure plate 1. The ink 30 remaining without being filled in the portion 4 can be released downward. By providing such ink discharge holes 9 a, 9 b, 9 c, it is possible to prevent the ink 30 remaining without filling the pattern portion 4 on the gravure plate 1 from adhering to the transfer roll 24.
The shape of each ink discharge hole 9a, 9b, 9c is not particularly limited, and may be, for example, a through hole or a non-through hole.
In addition, when using the printing machine 10 and forming the light emitting layer 38 of the organic light emitting device 31 mentioned later on the transparent base material 32, the above-mentioned ink discharge hole 9 does not necessarily need to be provided. When the ink discharge hole 9 is not provided, the ink 30 remaining without being filled in the pattern portion 4 is an unnecessary portion of the transparent base material 32 in the gravure plate 1 (such as a portion that is cut off when the organic light emitting device 31 is assembled). ) Is collected in the part corresponding to. For this reason, even if it is a case where the ink 30 which was not filled with the pattern part 4 was printed on the transparent base material 32 of the organic light emitting device 31, the said ink 30 does not produce a problem.

Each cell of the pattern portion of the gravure plate Next, with reference to FIGS. 2 and 3, each cell 2 of the pattern portion 4 of the gravure plate 1 will be described in detail. FIG. 2 is a plan view for explaining one embodiment of each cell 2 of the gravure plate 1 of the present invention. As described above, each picture part 4 of the gravure plate 1 includes a plurality of cells 2 that are arranged on the upper surface of the gravure plate 1 and are filled with the ink 30 from the ink supply unit 7. And ratio L / S of the width (cell part length L) of each cell 2 (the part which attached the oblique line) and the width | variety (non-cell part length S) of the non-cell part 3 is 0.8-100, Preferably 1- It is within the range of 60. The width of the cell 2 (cell part length L) is in the range of 10 to 500 μm, preferably 30 to 300 μm, and the width of the non-cell part 3 (non-cell part length S) is 2 to 500 μm, preferably 5 to 5 μm. The depth of the cell 2 (plate depth) is 20 to 200 μm, preferably 30 to 100 μm.
In addition, although the example in which each picture part 4 of the gravure plate 1 is composed of a plurality of cells 2 is shown, the present invention is not limited to this, and each picture part 4 is made a single cell according to the dimensions of each picture part 4. 2 can also be formed.

Further, as shown in FIG. 3A, the gravure plate 1 of the present invention is orthogonal to the width b of the printing direction (direction indicated by the arrow P in the figure) and the printing direction in each cell 2 (the hatched portion). The ratio b / a of the width “a” in the direction to be applied is 0.6 or more, and the upper limit is not particularly limited. In the present invention, the printing direction is synonymous with the rotation direction of the transfer roll 24.
2 and 3A show examples in which each cell 2 having a stripe shape extends in parallel with the printing direction P, but the present invention is not limited to this. For example, as shown in FIGS. 3B and 3C, the direction in which each cell 2 extends and the printing direction P need not be parallel. Also in this case, as shown in FIGS. 3B and 3C, the width b in the printing direction (direction indicated by the arrow P in the drawing) in each cell 2 (the hatched portion) is orthogonal to the printing direction. The ratio b / a of the width a is 0.6 or more.

  If the ratio L / S of the cell part length L to the non-cell part length S in the gravure plate 1 is less than 0.8, it is difficult to form a thick film, and if it exceeds 100, the cell formation of the gravure plate 1 is difficult. In addition, the variation in film thickness is undesirably large. Moreover, if the width of the cell 2 (cell portion length L) is less than 10 μm, it is difficult to form a thick film, and if it exceeds 500 μm, the variation in the film thickness becomes unfavorable. Further, if the width of the non-cell portion 3 (non-cell portion length S) is less than 2 μm, it is difficult to form a cell of the gravure plate 1, and if it exceeds 500 μm, the variation in film thickness is large and it is difficult to form a thick film. It is not preferable.

  Further, if the depth of the cell 2 (plate depth) is less than 20 μm, it is difficult to form a thick film, and even if the plate depth exceeds 200 μm, the thickness of the coating film to be formed does not increase. Further, if the ratio b / a is less than 0.6, it is difficult to form a thick film, and it is difficult to form a light emitting layer having a thickness of 70 nm or more in the formation of a light emitting layer described later.

(Transfer roll)
Next, the transfer roll 24 will be described in detail with reference to FIG.
As shown in FIG. 4, the transfer roll 24 includes a blanket cylinder 25 that rotates in the direction indicated by the arrow R, and a blanket 23 that is provided on the peripheral surface of the blanket cylinder 25. The blanket 23 receives the ink 30 from the pattern portion 4 of the gravure plate 1 and transfers the ink 30 onto the base material 32. The blanket 23 is made of an elastic material.

The blanket 23 is preferably made of a resin film 23a having a surface tension of 35 dyne / cm or more. As shown in FIG. 4, the resin film 23 a constituting the blanket 23 is integrally provided on the peripheral surface of the blanket cylinder 25 of the transfer roll 24. As shown in FIG. 4, the outer surface of the blanket 23 is flat over the entire blanket 23. The outer surface 27b is an ink receiving surface that receives the ink 30 from the pattern portion 4 of the gravure plate 1, and the ink 30 is received on the outer surface 27b with a pattern according to the pattern of the pattern portion 4 of the gravure plate 1. Is done. The circumferential length t ₁ of the transfer roll 24 is the circumferential length of the outer surface 23 b of the blanket 23.

  If the surface tension of the resin film 23a constituting the blanket 23 is less than 35 dyne / cm, ink acceptability from the gravure plate 1 is lowered. For this reason, it becomes difficult to transfer the ink 30 to the base material 32 with a uniform thickness. The surface tension (solid surface tension [γs]) of the resin film 23a is calculated, for example, by using an automatic contact angle meter (DropMaster 700 type, manufactured by Kyowa Interface Science Co., Ltd.). In this case, first, using a liquid (standard substance) having two or more kinds of surface tensions, the contact angle θ is measured with an automatic contact angle meter, and then γs (solid surface tension) = γL The surface tension of the resin film 23a is calculated based on the formula (surface tension of liquid) cos θ + γSL (surface tension of solid liquid).

  Examples of the resin film 23a used include a polyethylene terephthalate film, an easily adhesive type polyethylene terephthalate film, a polyethylene terephthalate film subjected to corona treatment, a polyphenylene sulfide film, a polyphenylene sulfide film subjected to corona treatment, a polyethylene naphthalate film, Examples thereof include resin films such as adhesive type polyethylene naphthalate film, polynorbornene film, and melamine baked polyethylene terephthalate film. The thickness of the resin film 23a can be, for example, in the range of 5 to 200 μm, preferably 10 to 100 μm. When the thickness of the resin film 23a is less than 5 μm, the film processability and the mounting property to the blanket cylinder 25 are not preferable. On the other hand, when the thickness of the resin film 23a exceeds 200 μm, the hardness becomes too high, and the flexibility is lowered, which is not preferable.

A cushion layer (not shown) may be interposed between the blanket cylinder 25 and the resin film 23a. In this case, the hardness of the cushion layer can be, for example, in the range of 20 to 80 ° , and the thickness of the cushion layer can be in the range of, for example, 0.1 to 30 mm. In addition, said hardness is TypeA hardness by a JIS (K6253) durometer hardness test.

〔ink〕
Next, the ink 30 used in the printing machine 10 in the present embodiment will be described in detail. The ink 30 is composed of a solvent and a solid content dissolved in the solvent. As the ink 30, an ink 30 having a viscosity (ink temperature 23 ° C.) at a shear rate of 100 / sec in a range of 5 to 200 cP is used.
If the viscosity of the ink 30 at a shear rate of 100 / sec (ink temperature 23 ° C.) is less than 5 cP, ink sag occurs or formation of a layer with a desired thickness becomes difficult. On the other hand, if it exceeds 200 cP, the unevenness due to the cells of the gravure plate 1 becomes large, and it becomes difficult to form a layer having a uniform thickness. The above viscosity measurement is performed in a steady flow measurement mode at a measurement temperature of 23 ° C. using a viscoelasticity measuring device MCR301 type manufactured by Physica. In the ink 30, the ratio (V1 / V2) of the viscosity (ink temperature 23 ° C.) V1 at a shear rate of 100 / sec and the viscosity (ink temperature 23 ° C.) V2 at a shear rate of 1000 / sec is 0.9 to 1. It is preferable that it is about .5. By setting the ratio (V1 / V2) within the above range, the ink 30 exhibits a Newtonian flow.

In addition, in the ink 30 used in the printing machine 10, it is preferable that the surface tension of the solvent used is 40 dyne / cm or less and the boiling point is in the range of 150 to 250 ° C.
If the surface tension of the solvent used in the ink 30 exceeds 40 dyne / cm, it is considered that the acceptability of the ink 30 from the gravure plate 1 to the transfer roll 24 is lowered, which is not preferable. Furthermore, when the boiling point of the solvent of the ink 30 is less than 150 ° C., the ink 30 transferred from the transfer roll 24 to the base material 32 is immediately dried, and thereby, streaks are likely to occur in the layer formed by the ink 30. It is possible to become. Further, when the boiling point of the solvent of the ink 30 exceeds 250 ° C., it is difficult to dry the ink 30, and the influence on the base material 32 and the like due to drying in the drying zone may occur, and the solvent may remain. Is not preferable. In addition, the measurement of the surface tension of a solvent shall be performed by 20 degreeC of liquid temperature by the surface tension meter CBVP-Z type | mold made by Kyowa Interface Science Co., Ltd.

(Solid content of ink)
The solvent and solid content used in the ink 30 are appropriately selected according to the layer formed on the substrate 32 by the printing machine 10. For example, when the light emitting layers 38R, 38G, 38B of the light emitting element layer 36 of the organic light emitting device 31 are formed by the printing machine 10 as will be described later, the solid content of the inks 30R, 30G, 30B for the light emitting layers 38R, 38G, 38B. Examples of the dye system, metal complex system, and polymer system are as follows.
(1) Dye-based luminescent materials cyclopentadiene derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, silole derivatives, thiophene ring compounds, pyridine rings Examples thereof include compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, and pyrazoline dimers.

(2) Metal complex light emitting material Aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethylzinc complex, porphyrin zinc complex, europium complex, central metal such as Al, Zn, Be, or the like , Tb, Eu, Dy and the like, and a metal complex having oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure and the like as a ligand.

(3) Polymer-based light-emitting material Examples include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinylcarbazole derivatives, polyfluorene derivatives, and the like.
The solid content in the light emitting layer ink 30 is preferably set in the range of 1.5 to 4.0% by weight.

(Ink solvent)
Moreover, when forming the light emitting layer 38 of the light emitting element layer 36 of the organic light emitting device 31 by the printing machine 10, the surface tension satisfies the above range (40 dyne / cm or less) as the solvent of the ink 30, and the boiling point is Those satisfying the above range (150 to 250 ° C.), such as cumene, anisole, n-propylbenzene, mesitylene, 1,2,4-trimethylbenzene, limonene, p-cymene, o-dichlorobenzene, butylbenzene, Use diethylbenzene, 2,3-dihydrobenzofuran, methyl benzoate, 1,2,3,4-tetramethylbenzene, amylbenzene, tetralin, ethyl benzoate, phenylhexane, cyclohexylbenzene, butyl benzoate, etc. alone Can do. Moreover, when using a mixed solvent, the surface tension and boiling point calculated by the ratio according to the mixing ratio satisfy | fill the said range. For example, in the case of a mixed solvent obtained by mixing a solvent 1 having a surface tension of Adyne / cm and a boiling point of B ° C. with a solvent 2 having a surface tension of Cdyne / cm and a boiling point of D ° C. of 3: 7, the mixing ratio The surface tension [(A × 3/10) + (C × 7/10)] calculated at a rate corresponding to the above satisfies the above range (40 dyne / cm or less) and calculated at a rate corresponding to the mixing ratio. The boiling point [(B × 3/10) + (D × 7/10)] must satisfy the above range (150 to 250 ° C.). Therefore, each solvent constituting the mixed solvent may have a surface tension and a boiling point outside the above ranges.

[Organic light emitting device]
Next, with reference to FIG. 5, the organic light emitting device 31 including the light emitting layer 38 formed by the printing machine 10 in the present embodiment will be described. FIG. 5 is a partial cross-sectional perspective view showing an embodiment of the organic light-emitting device of the present invention. In FIG. 5, the organic light emitting device 31 includes a transparent base material 32, a plurality of transparent electrode layers (first electrode layers) 33 having a strip-like pattern extending on the transparent base material 32 in the direction of arrow c, stripes, and the like. An insulating layer 34 having an opening 35 having a shape, a light emitting element layer 36 disposed so as to cover the transparent electrode layer 33 in the opening 35, and the transparent electrode layer 33 orthogonal to the light emitting element layer 36. Thus, a plurality of electrode layers 40 (second electrode layers) having a strip-like pattern extending in the arrow d direction are provided.
The opening 35 of the insulating layer 34 is a stripe-shaped opening along the direction of the arrow c, and is positioned on each transparent electrode layer 33 so that a desired portion of each transparent electrode layer 33 is exposed upward. ing.

The light emitting element layer 36 includes a hole injection layer 37 disposed so as to cover the insulating layer 34 and the transparent electrode layer 33 in each opening 35, and a transparent electrode layer 33 (hole injection in the opening 35). A plurality of light emitting layers 38 provided for each opening 35 so as to cover the insulating layer 34 at the periphery of the opening 35 and an electron injection layer provided so as to cover them. 39. In the illustrated example, the light emitting layer 38 includes a red light emitting layer 38R of the belt-shaped pattern, the green light emitting layer 38G, and a blue light emitting layer 38B, it is repeatedly arranged in pixel pitch t ₂ in this order. Among these, the red light emitting layer 38 </ b> R is formed of red ink 30 </ b> R printed by the printing machine 10 as described later. Similarly, the green light emitting layer 38G is formed from the green ink 30G printed by the printing machine 10, and the blue light emitting layer 38B is formed from the blue ink 30B printed by the printing machine 10. Pixel pitch _{t 2} is, e.g., in the range of 100 to 1000 [mu] m.
Although the electron injection layer 39 is formed so as to cover the insulating layer 34, it may be formed only in a region that is a lower layer of the electrode layer 40.

  Such an organic light emitting device 31 is a passive matrix type in which a portion where the transparent electrode layer 33 and the electrode layer 40 in a belt-like pattern intersect is a light emitting region, and the light emitting layer 38 (red light emitting layer 38R, The green light emitting layer 38G and the blue light emitting layer 38B) are formed by a light emitting layer forming method (described later) using the printer 10 of the present invention. And since the light emitting element layer 36 is formed so that the organic light emitting device 31 may run on the insulating layer 34 of the periphery of the opening part 35, the transparent electrode layer 33 and electrode layer which exist in the position which pinches | interposes the light emitting element layer 36 are formed. No short circuit with 40 occurs and the reliability is high.

  Next, each component of the organic light emitting device 31 will be described in detail.

(Transparent substrate)
First, the transparent substrate 32 will be described in detail. In the case of the bottom emission method, the transparent base material 32 is provided on the surface on the viewer side, and is made of a material having such a transparency that the viewer can easily see the light from the light emitting layer 38. When the direction in which the light from the light emitting layer 38 is extracted is the opposite direction (in the case of the top emission method), an opaque base material may be used instead of the transparent base material 32.
The transparent substrate 32 (including an opaque substrate instead) is made of a glass material, a resin material, or a composite material thereof, for example, a glass plate provided with a protective plastic film or a protective plastic layer Etc. are used.

Examples of the resin material and protective plastic material constituting the transparent substrate 32 include fluorine resin, polyethylene, polypropylene, polyvinyl chloride, polyvinyl fluoride, polystyrene, ABS resin, polyamide, polyacetal, polyester, polycarbonate, and modified polyphenylene ether. , Polysulfone, polyarylate, polyetherimide, polyamideimide, polyimide, polyphenylene sulfide, liquid crystalline polyester, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyoxymethylene, polyethersulfone, polyetheretherketone, polyacrylate, Acrylonitrile-styrene resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin Polyurethane, silicone resin, amorphous polyolefins, and the like. Even other resin materials can be used as long as they are polymer materials that can be used for organic light emitting devices.
The thickness of the transparent substrate 32 is usually about 50 μm to 1.1 mm.

  In such a transparent base material 32, although it depends on the use, it is more preferable if it has good gas barrier properties such as water vapor and oxygen. A gas barrier layer such as water vapor or oxygen may be formed on the transparent substrate 32. As such a gas barrier layer, for example, an inorganic oxide such as silicon oxide, aluminum oxide, titanium oxide or the like formed by a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method can be used.

(Transparent electrode layer)
Next, the transparent electrode layer 33 will be described in detail. In the example shown in FIG. 5, the transparent electrode layer 33 is an anode, and is disposed adjacent to the hole injection layer 37 in order to inject positive charges (holes) into the light emitting layer 38. Note that the transparent electrode layer 33 may be a cathode. In this case, the hole injection layer 37 and the electron injection layer 39 constituting the light emitting element layer 36 are alternately arranged.

The transparent electrode layer 33 is not particularly limited as long as it is used for a normal organic light emitting device, and a metal, an alloy, a mixture thereof, or the like can be used, for example, indium tin oxide (ITO), indium oxide. And thin film electrode materials such as indium zinc oxide (IZO), zinc oxide, stannic oxide, and gold. Among these, ITO, IZO, indium oxide, and gold which are transparent or translucent materials having a large work function (4 eV or more) are preferable so that holes can be easily injected.
The transparent electrode layer 33 preferably has a sheet resistance of several hundred Ω / □ or less, and depending on the material, the thickness of the transparent electrode layer 33 can be, for example, about 0.005 to 1 μm.
The transparent electrode layer 33 is arranged in a desired pattern shape from the peripheral terminal portion to the central pixel region. The transparent electrode layer 33 having such a pattern shape is formed by using a metal mask in a sputtering method, a vacuum evaporation method, or the like, or after forming a material for the transparent electrode layer on the entire surface, the photosensitive resist is masked. It is formed by etching.

(Insulating layer)
Next, the insulating layer 34 will be described in detail. The insulating layer 34 has a stripe-shaped opening 35 located on each transparent electrode layer 33. The insulating layer 34 is formed, for example, by first applying a photosensitive resin material over the entire surface so as to cover the transparent electrode layer 33, and then performing pattern exposure and development. Alternatively, the insulating layer 34 may be formed using a thermosetting resin material.
A portion where the insulating layer 34 is formed is a non-light emitting portion. Although the thickness of the insulating layer 34 can be appropriately set according to the insulation resistance specific to the resin constituting the insulating layer 34, it can be set to about 0.05 to 5.0 μm, for example. In addition, carbon black, titanium black pigment such as titanium nitride, titanium oxide, or titanium oxynitride, or two or more kinds of light-shielding fine particles are mixed with the above-described resin material to form a black matrix. The insulating layer 34 may be formed.
Note that the shape of the insulating layer 34 is not limited to the above-described shape.

(Light emitting element layer)
Next, the light emitting element layer 36 will be described in detail. In the example shown in FIG. 5, the light emitting element layer 36 has a structure in which a hole injection layer 37, a light emitting layer 38, and an electron injection layer 39 are laminated from the transparent electrode layer 33 side. However, it is not limited to such a structure, a structure composed of the light emitting layer 38 alone, a structure composed of the hole injection layer 37 and the light emitting layer 38, a structure composed of the light emitting layer 38 and the electron injection layer 39, A structure in which a hole transport layer is interposed between the hole injection layer 37 and the light emitting layer 38, a structure in which an electron transport layer is interposed between the light emitting layer 38 and the electron injection layer 39, or the like may be employed.
In addition, for the purpose of adjusting the light emission wavelength or improving the light emission efficiency, an appropriate material can be doped into each of the above layers.
Hereinafter, each layer of the light emitting element layer 36 will be described in detail.

In the example shown in FIG. 5, the light emitting layer 38 of the light emitting layer light emitting element layer 36 includes a red light emitting layer 38R, a green light emitting layer 38G, and a blue light emitting layer 38B. However, the structure is not limited to this, and a desired combination of a plurality of emission colors other than red light emission, green light emission, and blue light emission may be provided according to the purpose of use of the organic light emitting device 31. Good.
As the organic light emitting material used for the light emitting layers 38R, 38G, and 38B, the materials mentioned in the description of the solid content of the ink 30 can be appropriately used.

As described above, the hole injection layer 37 of the hole injection layer light emitting element layer 36 is disposed so as to cover the insulating layer 34 and the transparent electrode layer 33 in each opening 35. Examples of the hole injection material for forming the hole injection layer 37 include, for example, phenylamine, starburst amine, phthalocyanine, oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, amorphous carbon, and polyaniline. , Polythiophene derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazones Derivatives, stilbene derivatives, silazane derivatives, polysilanes, aniline copolymers, dielectric polymer oligomers such as thiophene oligomers, etc. Can.

  Furthermore, examples of the hole injection material include a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound. Examples of the porphyrin compound include polyfin, 1,10,15,20-tetraphenyl-21H, 23H-polyfin copper (II), aluminum phthalocyanine chloride, copper octamethylphthalocyanine, and the like. In addition, aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl, N, N′-diphenyl-N, N′-bis. (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine, 4- (di-p-tolylamino) -4 ′-[4 (di-p-tolylamino) styryl] stilbene, 3, -Methoxy-4'-N, N-diphenylaminostilbenzene, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl, 4,4 ', 4 "-tris [N- ( 3-methylphenyl) -N-phenylamino] triphenylamine and the like.

  The hole injection layer 37 formed of the above-described material is, for example, a mask having an opening corresponding to the image display region (a mask for preventing film formation on the electrode terminal formed of the transparent electrode layer 33 in the peripheral portion). ) Through a vacuum deposition method or the like. Alternatively, the hole injection layer 37 can be formed by a printing method such as a screen printing method.

Hole transport layer As a material for forming the hole transport layer, for example, oxadiazole, oxazole, triazole, thiazole, triphenylmethane, styryl, pyrazoline, hydrazone, aromatic amine, Examples thereof include carbazole, polyvinyl carbazole, stilbene, enamine, azine, triphenylamine, butadiene, polycyclic aromatic compound, and stilbene dimer.
Further, as the π-conjugated polymer, polyacetylene, polydiacetylene, poly (P-phenylene), poly (P-phenylene sulfide), poly (P-phenylene oxide), poly (1,6-heptadiene), poly (P— Phenylene vinylene), poly (2,5-thienylene), poly (2,5-pyrrole), poly (m-phenylene sulfide), poly (4,4'-biphenylene) and the like.
As the charge transfer polymer complex, polystyrene / AgC104, polyvinylnaphthalene / TCNE, polyvinylnaphthalene / P-CA, polyvinylnaphthalene / DDQ, polyvinylmesitylene / TCNE, polynaphthaacetylene / TCNE, polyvinylanthracene / Br2, polyvinylanthracene / I2 , Polyvinyl anthracene / TNB, polydimethylaminostyrene / CA, polyvinyl imidazole / CQ, poly-P-phenylene / I2, poly-1-vinylpyridine / I2, poly-4-vinylpyridine / I2, poly-P-1- Examples include phenylene, I2, polyvinylpyridium, TCNQ, and the like. Further, TCNQ-TTF and the like are exemplified as a charge transfer low molecular complex, and polycopper phthalocyanine and the like are exemplified as a polymer metal complex.
As the hole transport material, a material having a low ionization potential is preferable, and in particular, a butadiene system, an enamine system, a hydrazone system, and a triphenylamine system are preferable.

As an electron injection material for forming the electron injection layer 39, for example, calcium, barium, aluminum lithium, lithium fluoride, strontium, magnesium oxide, magnesium fluoride, strontium fluoride, calcium fluoride, barium fluoride, Heterocyclic tetracarboxylic acid anhydrides such as aluminum oxide, strontium oxide, calcium oxide, polymethyl methacrylate, sodium polystyrene sulfonate, nitro-substituted fluorene derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene , Carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the oxygen atom of the above oxadiazole ring placed on the sulfur atom Thiazole derivatives, quinoxaline derivatives having a quinoxaline ring known as electron-withdrawing groups, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum, phthalocyanines, metal phthalocyanines, distyrylpyrazine derivatives, etc. Can do. The electron injection layer 39 formed from such a material is, for example, a mask having an opening corresponding to an image display region (a mask for preventing film formation on an electrode terminal including the transparent electrode layer 33 in the peripheral portion). ) Through a vacuum deposition method or the like. The electron injection layer 39 can also be formed by a printing method such as a screen printing method.

  In addition, the formation of the hole injection layer 37 and the light emitting layer 38 is performed within 1 minute after the formation of the coating film for the hole injection layer 37. It can also be carried out by simultaneously drying in the range of ° C. In this case, the coating film for the hole injection layer 37 has a viscosity (ink temperature of 23 ° C.) at a shear rate of 100 / second in the range of 5 to 200 cP by the same method as the light emitting layer forming method of the present invention. The solvent can also be formed using a hole injection layer ink having a surface tension of 40 dyne / cm or less and a boiling point of 150 to 250 ° C.

  In addition, the thickness of each layer of the light emitting element layer 36 is not particularly limited, and can be, for example, about 10 to 1000 nm. Examples of materials doped in each layer of the light-emitting element layer 36 include, for example, perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, phenoxazone. And the like.

(Electrode layer)
Next, the electrode layer 40 will be described in detail. In the example shown in FIG. 5, the electrode layer 40 is a cathode, and is disposed adjacent to the electron injection layer 39 in order to inject negative charges (electrons) into the light emitting layer 38. Note that the electrode layer 40 may be an anode, and in this case, the hole injection layer 37 and the electron injection layer 39 constituting the light emitting element layer 36 are replaced with each other.
The material of the electrode layer 40 is not particularly limited as long as it is used for a normal organic light emitting device, and in the same manner as the transparent electrode layer 33 described above, indium tin oxide (ITO), indium oxide, oxidation Thin film electrode materials such as indium zinc (IZO), zinc oxide, stannic oxide, or gold, magnesium alloys (eg, MgAg), aluminum or alloys thereof (AlLi, AlCa, AlMg, etc.), silver, etc. be able to. Among them, a magnesium alloy, aluminum, silver, or the like having a small work function (4 eV or less) is preferable so that electrons can be easily injected. Such an electrode layer 40 preferably has a sheet resistance of several hundred Ω / □ or less. For this reason, the thickness of the electrode layer 40 can be, for example, about 0.005 to 0.5 μm.
The electrode layer 40 can be formed by forming a film into a pattern shape by a method such as a sputtering method or a vacuum deposition method through a mask using the electrode material described above.

  Next, the operation of the present embodiment having such a configuration will be described. Here, a method for forming the organic light emitting device 31 including the light emitting layer 38 will be described with reference to FIGS. 1, 5, and 6 </ b> A to 6 </ b> E.

  First, as shown in FIG. 5, a transparent electrode layer 33 having a desired pattern is formed on a transparent substrate 32. The method for forming the transparent electrode layer 33 is not particularly limited, and a method for forming the transparent electrode layer 33 having a desired pattern by a sputtering method, a vacuum evaporation method, or the like using a metal mask, or a transparent electrode layer After forming the material over the entire surface of the transparent substrate 32, a method of forming the transparent electrode layer 33 having a desired pattern by etching using a photosensitive resist as a mask is appropriately selected.

  Next, as shown in FIG. 5, an insulating layer 34 having a plurality of openings 35 that expose a desired portion of the transparent electrode layer 33 upward is formed on the transparent substrate 32. In this case, first, a photosensitive resin material is applied to the entire surface so as to cover the transparent electrode layer 33, and then pattern exposure and development are performed on the applied photosensitive resin material. In this way, the insulating layer 34 having a plurality of openings 35 is formed.

  Thereafter, as shown in FIG. 5, a hole injection layer 37 is formed so as to cover the transparent electrode layer 33 in the opening 35 and the insulating layer 34. The method for forming the hole injection layer 37 is not particularly limited. As described above, the hole injection layer 37 is formed by vacuum deposition or the like through a photomask having an opening corresponding to the image display region. Can do.

  Next, as shown in FIG. 5, a red light emitting layer 38R, a green light emitting layer 38G, and a blue light emitting layer 38B are formed on the hole injection layer 37. The light emitting layers 38R, 38G, and 38B are simultaneously formed using the printing machine 10 described above.

  Hereinafter, with reference to FIGS. 6A to 6E, a method for simultaneously forming the light emitting layers 38R, 38G, and 38B using the printing press 10 will be described in detail. First, the red ink 30R is supplied to the upper surface of the gravure plate 1 by the first ink supply unit 7a. In this case, the red ink 30R from the first ink supply unit 7a is supplied to the upstream portion of the first pattern portion 4a in the first region 15a. Next, as shown in FIG. 6A, the first doctor 8a is used to fill each cell 2 of the first picture portion 4a with the red ink 30R. At this time, the red ink 30R remaining without being filled in each cell 2 of the first pattern portion 4a is dropped into the first ink discharge hole 9a by the first doctor 8a.

  Next, the transfer roll 24 is caused to travel in the first region 15 a of the gravure plate 1. Accordingly, as shown in FIG. 6B, the transfer roller 24 receives the red ink 30R of the first pattern portion 4a in the first region 15a. At this time, as described above, the red ink 30R remaining without being filled in each cell 2 of the first picture portion 4a is dropped by the first doctor 8a into the first ink discharge hole 9a. This prevents red ink 30R other than red ink 30R filled in the first picture part 4a from being received by the transfer roll 24.

  Further, while the transfer roll 24 is running in the first region 15a of the gravure plate 1, the green ink 30G is supplied to the upper surface of the gravure plate 1 by the second ink supply unit 7b. In this case, the green ink 30G from the second ink supply part 7b is supplied between the second picture part 4b in the second area 15b and the first picture part 4a in the first area 15a. Next, as shown in FIG.6 (b), the green ink 30G is filled into each cell 2 of the 2nd pattern part 4b using the 2nd doctor 8b. At this time, the green ink 30G remaining without being filled in each cell 2 of the second picture portion 4b is dropped into the second ink discharge hole 9b by the second doctor 8b.

  Thereafter, the transfer roll 24 is caused to travel in the second region 15 b of the gravure plate 1. As a result, as shown in FIG. 6C, the transfer roller 24 receives the green ink 30G in the second pattern portion 4b of the second region 15b. At this time, as shown in FIG. 6C, the second pattern portion 4b of the second region 15b is shifted in the width direction with respect to the first pattern portion 4a of the first region 15a. Thereby, it is possible to prevent the green ink 30G received by the transfer roll 24 from the second pattern portion 4b of the second region 15b from being mixed with the red ink 30R on the transfer roll 24.

  Moreover, as shown in FIG.6 (c), the 2nd area | region 15b is provided with the recessed part 14a in the part which overlaps with the 1st pattern part 4a of the 1st area | region 15a in the width direction. For this reason, when the transfer roll 24 runs in the second region 15b of the gravure plate 1, the red ink 30R received by the transfer roll 24 from the first pattern portion 4a of the first region 15a adheres to the second region 15b. There is nothing. This can prevent the thickness of the red ink 30R received by the transfer roll 24 from decreasing. In addition, the red ink 30R received by the transfer roll 24 can be prevented from being mixed with the green ink 30G on the second region 15b.

  Further, while the transfer roll 24 is running in the second region 15b of the gravure plate 1, the blue ink 30B is supplied to the upper surface of the gravure plate 1 by the third ink supply unit 7c. In this case, the blue ink 30B from the third ink supply unit 7c is supplied between the third pattern portion 4c in the third region 15c and the second pattern portion 4b in the second region 15b. Next, as illustrated in FIG. 6C, the blue ink 30 </ b> B is filled into each cell 2 of the third picture portion 4 c using the third doctor 8 c. At this time, the blue ink 30B remaining without being filled in each cell 2 of the third picture portion 4c is dropped into the third ink discharge hole 9c by the third doctor 8c.

  Thereafter, the transfer roll 24 is caused to travel in the third region 15 c of the gravure plate 1. As a result, as shown in FIG. 6D, the blue ink 30B of the third pattern portion 4c in the third region 15c is received by the transfer roll 24. At this time, as shown in FIG. 6D, the third pattern portion 4c of the third region 15c is wider than the first pattern portion 4a of the first region 15a and the second pattern portion 4b of the second region 15b. It is displaced in the direction. Thereby, it is possible to prevent the blue ink 30B received by the transfer roll 24 from the third pattern portion 4c in the third region 15c from being mixed with the red ink 30R and the green ink 30G on the transfer roll 24.

  Further, as shown in FIG. 6D, the third region 15b is provided with a recess 14b in a portion overlapping the first pattern portion 4a of the first region 15a in the width direction, and the second region 15b has a second portion. A concave portion 14c is provided in a portion overlapping the two pattern portions 4b in the width direction. For this reason, when the transfer roll 24 runs in the third region 15c of the gravure plate 1, the red ink 30R received by the transfer roll 24 from the first pattern portion 4a does not adhere to the third region 15c, and The green ink 30G received by the transfer roll 24 from the second pattern portion 4b of the second region 15b does not adhere to the third region 15c. This can prevent the thickness of the red ink 30R and the green ink 30G received by the transfer roll 24 from being reduced. In addition, it is possible to prevent the red ink 30R and the green ink 30G received by the transfer roll 24 from being mixed with the blue ink 30B on the third region 15c.

Thereafter, the inks 30R, 30G, and 30B on the transfer roll 24 are transferred onto the transparent substrate 32 as shown in FIG. Thereby, the light emitting layers 38R, 38G, and 38B made of the respective inks 30R, 30G, and 30B can be simultaneously formed. In this case, as shown in FIG. 6E, the pixel pitch of the light emitting layers 38R, 38G, and 38B in the width direction is between the pattern part 4 in one area of the gravure plate 1 and the pattern part 4 in the other area. It is determined by the interval t ₂ in the width direction. For this reason, it is possible to form the light emitting layers 38R, 38G, and 38B in a short time and with high accuracy compared to the case where the light emitting layers of a plurality of colors are sequentially formed using different printing machines for each type of ink.

  Thereafter, as shown in FIG. 5, an electron injection layer 39 is formed so as to cover the hole injection layer 37 and the light emitting layer 38. The method for forming the electron injection layer 39 is not particularly limited. For example, as in the case of forming the hole injection layer 37, a vacuum deposition method is used through a photomask having an opening corresponding to the image display region. It can be formed by film formation.

  Finally, the electrode layer 40 is formed in a predetermined pattern shape so as to be connected to the light emitting element layer 36 located in the desired opening 35 of the light emitting element layer 36. In this way, the organic light emitting device 31 shown in FIG. 5 is formed.

As described above, according to the present embodiment, the gravure plate 1 includes a plurality of pieces each having the same length as the circumferential length t ₁ of the transfer roll 24 along the traveling direction (printing direction P) of the transfer roll 24. It is divided into areas 15a, 15b, 15c. Further, different types of inks 30R, 30B, and 30G are supplied to the pattern portions 4a, 4b, and 4c of the regions 15a, 15b, and 15c, respectively. Furthermore, the pattern portion 4 in one region 15 of the gravure plate 1 is shifted in the width direction with respect to the pattern portion 4 in the other region 15. For this reason, each of the inks 30R, 30B, and 30G can be received by the transfer roll 24 so that the inks 30R, 30B, and 30G are arranged in the width direction.

  Further, according to the present embodiment, the second region 15b and the third region 15c that are downstream of the most upstream first region 15a among the regions 15a, 15b, and 15c of the gravure plate 1 are further upstream. Concave portions 14 are provided in portions overlapping the respective picture portions in the width direction in the width direction. The concave portion 14 can prevent the ink 30 received by the transfer roll 24 in the upstream region from adhering to the downstream region. As a result, the plurality of types of inks 30R, 30B, and 30G received by the transfer roll 24 can be transferred onto the substrate 52 at once while maintaining a desired thickness.

  Further, according to the present embodiment, the doctors 8a, 8b, and 8c are provided in the regions 15a, 15b, and 15c of the gravure plate 1, respectively. Therefore, when the inks 30R, 30B, and 30G are scratched by the doctors 8a, 8b, and 8c, it is possible to reliably prevent different types of inks from being mixed.

  Further, according to the present embodiment, the ink discharge holes 9a, 9b, 9c are provided in the regions 15a, 15b, 15c of the gravure plate 1 on the downstream side of the pattern portions 4a, 4b, 4c. By these ink discharge holes 9a, 9b, 9c, the inks 30R, 30B, 30G remaining without being filled in the pattern portions 4a, 4b, 4c can be released downward. As a result, it is possible to prevent the inks 30R, 30B, 30G remaining on the gravure plate 1 from remaining in the pattern portions 4a, 4b, 4c from adhering to the transfer roll 24.

  In addition, according to the present embodiment, in the organic light emitting device including the light emitting element layer having at least the light emitting layer, the light emitting layers 38R, 38B, and 38G of a plurality of colors are formed by the printing machine 10 described above. For this reason, the light emitting layers 38R, 38B, and 38G of a plurality of colors can be formed by one printing. Therefore, it is possible to form the light emitting layers 38R, 38B, and 38G of a plurality of colors in a shorter time and with higher accuracy than when the light emitting layers 38R, 38B, and 38G of each color are sequentially formed using a plurality of printers. it can.

[Comparative example]
Next, with reference to FIGS. 7A and 7B, the effect of the present invention will be described in comparison with a comparative example. FIG. 7A is a diagram illustrating the printing press 100 in the comparative example, and FIG. 8B is a diagram illustrating a state in which a plurality of types of ink are filled in the pattern portion in the printing press 100 of the comparative example. is there.

  The printing press 100 in the comparative example shown in FIGS. 7A and 7B is different only in that the pattern portions filled with the inks 30R, 30G, and 30B are arranged in the width direction. These are substantially the same as the printing press 10 in the present embodiment shown in FIGS. In the printing machine 100 of the comparative example, the same parts as those of the printing machine 10 of the present embodiment shown in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7A, the gravure plate 101 of the printing machine 100 includes a first picture portion 104a filled with red ink 30R, a second picture portion 104b filled with green ink 30G, and a blue ink 30B. And a third pattern portion 104c filled with the. These pattern parts 104a, 104b, and 104c are arranged in the width direction as shown in FIG.

  Let us consider the operation when the pattern portions 104a, 104b, and 104c are filled with the inks 30R, 30G, and 30B in the printing machine 100. Here, attention is paid to the pattern portions 104a and 104b among the pattern portions. In this case, the pattern parts 104a and 104b are provided so as to be arranged in the width direction. Therefore, as shown in FIG. 7B, the pattern parts 104a and 104b are filled with ink 30R and 30G by the doctors 8a and 8b. At this time, it is considered that the red ink 30R and the green ink 30G are mixed. When such a color mixture occurs, the characteristics relating to the color purity of the light emitting layer formed from the ink deteriorate.

On the other hand, according to the present invention, as described above, each of the gravure plates 1 of the printing machine 10 has a circumferential length t _{1 of the} transfer roll 24 along the traveling direction (printing direction P) of the transfer roll 24. It is divided into a plurality of regions 15a, 15b, 15c having the same length. Further, different types of inks 30R, 30B, and 30G are supplied to the pattern portions 4a, 4b, and 4c of the regions 15a, 15b, and 15c, respectively. Furthermore, the pattern portion 4 in one region 15 of the gravure plate 1 is shifted in the width direction with respect to the pattern portion 4 in the other region 15. For this reason, it is possible to prevent color mixing of the inks 30R, 30B, and 30G on the gravure plate 1.

[Modification of printing press]
Modification 1 of printing machine
In the printing machine 10 according to the present embodiment, an example in which gravure offset printing is performed by a combination of the gravure plate 1 and the transfer roll 24 is shown. However, the present invention is not limited to this, and the printing machine 10 may be a printing machine that performs gravure printing (direct gravure printing). In this case, the base material 52 that is the printing object is provided integrally on the surface of the transfer roll 24. For this reason, the inks 30R, 30G, and 30B filled in the pattern portions 4a, 4b, and 4c of the gravure plate 1 are directly transferred to the substrate 52 on the transfer roll 24. In this manner, a plurality of types of inks 30R, 30G, and 30B can be simultaneously printed on the substrate 52.

Modification 2 of printing machine
Further, the printing press 10 of the present invention may be a printing press that performs flexographic printing. In this case, as shown in FIG. 8, the transfer roll of the printing press 10 includes a plate cylinder 24a having a flexographic plate 26 having a convex portion on its outer periphery. In the printing press 10 shown in FIG. 8, the inks 30R, 30G, and 30B of the gravure plate 1 (ink plate) are respectively received by the convex portions of the flexographic plate 26 of the plate cylinder 24a. Thereafter, the inks 30R, 30G, 30B on the convex portions of the flexographic plate 26 are simultaneously transferred onto the substrate 32 with a pattern corresponding to the convex pattern of the flexographic plate 26.

Modification 3 of printing machine
Moreover, in the printing machine 10 by this Embodiment, the example in which the base material 32 was mounted on the flat base material surface plate 6 was shown. However, the present invention is not limited to this, and as shown in FIG. 9, the substrate 32 may be sandwiched between the transfer roll 24 and the roll-shaped impression cylinder 6a. In this case, as in the case of the printer 10 shown in FIGS. 1 to 6, first, the inks 30 </ b> R, 30 </ b> B, and 30 </ b> G on the upper surface of the gravure plate 1 are sequentially received by the transfer roll 24. Next, the inks 30R, 30B, and 30G on the transfer roll 24 are transferred onto the base material 32 being conveyed on the impression cylinder 6a.

Modification 4 of printing machine
Moreover, in this Embodiment, the printing machine showed the example which consists of the printing machine 10 provided with the flat gravure plate 1 (ink plate) which has the cell 2 on the upper surface. However, the present invention is not limited to this, and as shown in FIG. 10, the printing machine may include a printing machine 10 </ b> A provided with a roll-shaped gravure plate 1 </ b> A (ink plate) having cells on its outer peripheral surface. . Hereinafter, the printing press 10A will be described.

The printing machine 10A shown in FIG. 10 receives a roll-shaped gravure plate 1A having cells 2 on its outer peripheral surface, ink 30 in the cells 2 in contact with the gravure plate 1A, and transfers ink onto a substrate 32. A transfer roll 24 to be moved, and an impression cylinder 6 a for sandwiching the base material 32 between the transfer roll 24. Further, as shown in FIG. 10, the gravure plate 1A is along the rotational direction R of the gravure plate 1A, a first region 15a having a length each corresponding to the circumferential length t ₁ of the transfer roll 24, a second region 15b And it is divided into the 3rd field 15c. In the printing machine 10A shown in FIG. 10, the same parts as those of the printing machine 10 shown in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Next, a method for forming the light emitting layers 38R, 38G, and 38B on the transparent substrate 32 using the printing machine 10A will be described with reference to FIGS.

  11A to 11D are views when the printing press 10A shown in FIG. 10 is viewed from the direction of the arrow XI, and are diagrams illustrating a method for forming the light emitting layers 38R, 38G, and 38B.

  First, the first ink supply unit 7a supplies red ink 30R to the outer peripheral surface of the gravure plate 1A. In this case, the red ink 30R from the first ink supply unit 7a is supplied to the upstream portion of the first pattern portion 4a in the first region 15a. Next, as shown in FIG. 11A, the first doctor 8a is used to fill the red ink 30R into each cell 2 of the first picture portion 4a. At this time, the red ink 30R remaining without being filled in each cell 2 of the first pattern portion 4a is dropped into the first ink discharge hole 9a by the first doctor 8a.

  Thereafter, the first region 15a of the gravure plate 1A and the transfer roll 24 are brought into contact with each other. Accordingly, as shown in FIG. 11B, the transfer roller 24 receives the red ink 30R of the first pattern portion 4a in the first region 15a. At this time, as described above, the red ink 30R remaining without being filled in each cell 2 of the first picture portion 4a is dropped by the first doctor 8a into the first ink discharge hole 9a. This prevents red ink 30R other than red ink 30R filled in the first picture part 4a from being received by the transfer roll 24.

  Further, while the first region 15a of the gravure plate 1 and the transfer roll 24 are in contact with each other, the second ink supply unit 7b supplies the green ink 30G to the outer peripheral surface of the gravure plate 1A. In this case, the green ink 30G from the second ink supply part 7b is supplied between the second picture part 4b in the second area 15b and the first picture part 4a in the first area 15a. Next, as shown in FIG. 11B, using the second doctor 8b, the green ink 30G is filled into each cell 2 of the second picture portion 4b. At this time, the green ink 30G remaining without being filled in each cell 2 of the second picture portion 4b is dropped into the second ink discharge hole 9b by the second doctor 8b.

  Thereafter, the second region 15b of the gravure plate 1 and the transfer roll 24 are brought into contact with each other. Accordingly, the green ink 30G of the second pattern portion 4b in the second region 15b is received by the transfer roll 24. At this time, as shown in FIG. 11B, the second pattern portion 4b of the second region 15b is shifted in the width direction with respect to the first pattern portion 4a of the first region 15a. Thereby, it is possible to prevent the green ink 30G received by the transfer roll 24 from the second pattern portion 4b of the second region 15b from being mixed with the red ink 30R on the transfer roll 24.

  As shown in FIG. 11B, the second region 15b is provided with a recess 14a in a portion overlapping the first pattern portion 4a of the first region 15a in the width direction. Therefore, when the second area 15b of the gravure plate 1 and the transfer roll 24 are brought into contact with each other, the red ink 30R received by the transfer roll 24 from the first pattern portion 4a of the first area 15a is applied to the second area 15b. It will not adhere. This can prevent the thickness of the red ink 30R received by the transfer roll 24 from decreasing. In addition, the red ink 30R received by the transfer roll 24 can be prevented from being mixed with the green ink 30G on the second region 15b.

  Further, while the second region 15b of the gravure plate 1 and the transfer roll 24 are in contact with each other, the blue ink 30B is supplied to the outer peripheral surface of the gravure plate 1 by the third ink supply unit 7c. In this case, the blue ink 30B from the third ink supply unit 7c is supplied between the third pattern portion 4c in the third region 15c and the second pattern portion 4b in the second region 15b. Next, as shown in FIG.11 (c), using the 3rd doctor 8c, the blue ink 30B is filled into each cell 2 of the 3rd pattern part 4c. At this time, the blue ink 30B remaining without being filled in each cell 2 of the third picture portion 4c is dropped into the third ink discharge hole 9c by the third doctor 8c.

  Thereafter, the third region 15 c of the gravure plate 1 is brought into contact with the transfer roll 24. As a result, the blue ink 30 </ b> B of the third pattern portion 4 c in the third region 15 c is received by the transfer roll 24. At this time, as shown in FIG. 11C, the third pattern portion 4c of the third region 15c is wider than the first pattern portion 4a of the first region 15a and the second pattern portion 4b of the second region 15b. It is displaced in the direction. Thereby, it is possible to prevent the blue ink 30B received by the transfer roll 24 from the third pattern portion 4c in the third region 15c from being mixed with the red ink 30R and the green ink 30G on the transfer roll 24.

  As shown in FIG. 11C, the third region 15b is provided with a recess 14b in a portion overlapping the first pattern portion 4a of the first region 15a in the width direction, and the second region 15b A concave portion 14c is provided in a portion overlapping the two pattern portions 4b in the width direction. For this reason, when the 3rd area | region 15c of the gravure plate 1 and the transfer roll 24 contact | abut, the red ink 30R received by the transfer roll 24 from the 1st pattern part 4a does not adhere to the 3rd area | region 15c, Further, the green ink 30G received by the transfer roll 24 from the second picture portion 4b of the second region 15b does not adhere to the third region 15c. This can prevent the thickness of the red ink 30R and the green ink 30G received by the transfer roll 24 from being reduced. In addition, it is possible to prevent the red ink 30R and the green ink 30G received by the transfer roll 24 from being mixed with the blue ink 30B on the third region 15c.

  Thereafter, as shown in FIG. 11 (d), the inks 30 R, 30 G, and 30 B on the transfer roll 24 are transferred onto the transparent substrate 32. Thereby, the light emitting layers 38R, 38G, and 38B made of the respective inks 30R, 30G, and 30B can be simultaneously formed. As a result, the light emitting layers 38R, 38G, and 38B can be formed in a shorter time and with higher accuracy than when the light emitting layers of a plurality of colors are sequentially formed using different printing machines for each type of ink.

[Modification of gravure cell]
Further, in the above-described form, the gravure plate (ink plate) has a plurality of cells 2 filled with the ink 30 from the ink supply unit 7, and each cell 2 has a striped shape. An example consisting of However, the gravure plate is not limited to this, and the gravure plate may be composed of a gravure plate 11 having a plurality of cells 12 which are arranged in a grid and filled with ink 30 from the ink supply unit 7.

  FIG. 12 is a view for explaining a gravure plate 11 which is another embodiment of the gravure plate (ink plate) of the present invention. The gravure plate 11 shown in FIG. 12 has a shape in which the cells 12 are partitioned into a plurality of parts (in the example shown in FIG. 12, each cell 12 is a square), and there is a non-cell portion 13 between the cells 12. . FIG. 13 is a diagram for explaining another form of the gravure plate 11. The gravure plate 11 shown in FIG. 13 has a shape in which cells 12 are partitioned into a plurality of cells, each cell 12 has a diamond shape, and a non-cell portion 13 exists between the cells 12. Further, FIG. 14 is a diagram for explaining another form of the gravure plate 11. The gravure plate 11 shown in FIG. 14 has a shape in which cells 12 are divided into a plurality of cells, each cell 12 is elliptical, and a non-cell portion 13 exists between the cells 12.

  The gravure plate 11 shown in FIGS. 12 to 14 has a maximum width b in the direction perpendicular to the printing direction and the maximum width b in the printing direction (direction indicated by the arrow P in the drawing) in each cell 12 (shaded area). The ratio b / a of a is 0.6 or more, preferably 0.8 or more, and the upper limit is not particularly limited. Further, the total cell area occupying the film forming site is in the range of 55 to 95%, preferably 60 to 90%, and the width of the non-cell portion 13 (non-cell portion length S1, S2) is 2 to 500 μm, preferably 10 The depth of the cell 12 (plate depth) is 20 to 200 μm, preferably 30 to 100 μm.

If the ratio b / a is less than 0.6, it is difficult to form a thick film, and it becomes difficult to form the light emitting layer 38 having a thickness of 70 nm or more in the formation of the light emitting layer 38. Further, if the total cell area in the film formation site is less than 55%, it is difficult to form a thick film, and if it exceeds 95%, the film thickness variation is unfavorable. In addition, if the width of the non-cell portion 13 (non-cell portion length S1, S2) is less than 2 μm, it is difficult to form the cell 12 of the gravure plate 11, and if it exceeds 500 μm, the variation in film thickness increases. Thick film formation is difficult, which is not preferable. Further, if the depth of the cell 12 (plate depth) is less than 20 μm, it is difficult to form a thick film, and even if the plate depth exceeds 200 μm, the thickness of the coating film to be formed does not increase.
In addition, the shape of the cell 12 of the gravure plate 11 described above is an example, and is not limited to the above-described form.

[Modification of organic light-emitting device]
Moreover, in this Embodiment, the organic light-emitting device showed the example which is the passive matrix organic light-emitting device 31 from which the site | part which the transparent electrode layer 33 and the electrode layer 40 of a strip | belt-shaped pattern cross | intersect becomes a light emission area. However, the present invention is not limited to this, and the organic light emitting device may be an active matrix type.

  FIG. 15 and FIG. 16 are diagrams for explaining an example of an active matrix type organic light emitting device of the present invention. FIG. 15 is a diagram showing an electrode wiring pattern. An electrode wiring pattern 53 formed on a transparent substrate (not shown) includes a signal line 53A, a scanning line 53B, a TFT (thin film transistor) 53C, and a transparent electrode (pixel electrode). ) Layer 53D. Further, an insulating layer 54 (the hatched portion in FIG. 15) is formed so as to cover these electrode wiring patterns 53, and this insulating layer 54 has an opening 55 located on each transparent electrode layer 53D. It has. A light emitting element layer (not shown) is formed on the insulating layer 54 so as to cover the transparent electrode layer 53D in each opening 55, and an electrode (common electrode) layer (not shown) is formed on the light emitting element layer. Is provided.

  The light emitting element layer includes a hole injection layer disposed so as to cover the insulating layer 54 and the transparent electrode layer 53D in each opening 55, and a transparent electrode layer 53D (hole injection in the opening 55). A plurality of light emitting layers disposed for each opening 55 so as to ride on the insulating layer 54 at the periphery of the opening 55, and an electron injection layer disposed so as to cover these layers, It can consist of FIG. 16 is a diagram showing the relationship between the opening 55 of the insulating layer 54 and the light emitting layer. In FIG. 16, the light emitting layer includes a red light emitting layer 58R, a green light emitting layer 58G, and a blue light emitting layer 58B having a desired pattern shape larger than the opening 55.

In such an active matrix type organic light emitting device of the present invention, the light emitting layer (red light emitting layer 58R, green light emitting layer 58G, blue light emitting layer 58B) is formed by the method for forming a light emitting layer of the present invention. . And since the light emitting element layer is formed so that it may ride on the insulating layer 54 of the periphery of the opening part 55, short circuit with transparent electrode layer 53D and the electrode layer (not shown) which exist in the position which pinches | interposes a light emitting element layer. It is highly reliable without causing any problems. In addition, the light emitting layer of the light emitting element layer (red light emitting layer 58R, green light emitting layer 58G, blue light emitting layer 58B) is formed by the forming method of the present invention, and has a precise and uniform thickness (preferably a thickness). Variation is 10% or less). For this reason, high quality display is possible.
The light emitting element layer has a structure composed of a single light emitting layer, a structure composed of a hole injection layer and a light emitting layer, a structure composed of a light emitting layer and an electron injection layer, and A structure in which a hole transport layer is interposed between the hole injection layer and the light emitting layer, a structure in which an electron transport layer is interposed between the light emitting layer and the electron injection layer, and the like can be employed.

FIG. 17 is a partial perspective view showing another embodiment of the organic light-emitting device of the present invention, and FIG. 18 is a cross-sectional view taken along line AA of the organic light-emitting device shown in FIG. 17 and 18, the organic light emitting device 61 includes a transparent base 62, a transparent electrode layer 63 formed in a rectangular shape on the transparent base 62, a rhombus opening 65a, and a rectangular opening 65b. An insulating layer 64 having a light emitting element layer 66 disposed so as to cover the transparent electrode layer 63 in each of the openings 65a and 65b, and an electrode layer 70 formed so as to cover the light emitting element layer 66. It has.
The light-emitting element layer 66 includes a hole injection layer 67, a light-emitting layer 68, and an electron injection layer 69 that are stacked, and is formed so as to run on the insulating layer 64 at the periphery of the openings 65a and 65b. ing.

  Such an organic light emitting device 61 is an area color display in which a portion where each opening 65a, 65b exists becomes a display region, and the light emitting layer 68 of the light emitting element layer 66 is formed by the method for forming a light emitting layer of the present invention. It has been done. In this organic light emitting device 61, since the light emitting element layer 66 is formed so as to run over the insulating layer 64 at the periphery of the openings 65a and 65b, the transparent electrode layer 63 and the electrode present at the position where the light emitting element layer 66 is sandwiched are formed. The short circuit with the layer 70 does not occur and the reliability is high. Further, the light emitting layer 68 of the light emitting element layer 66 is formed by the formation method of the present invention, and is formed with high accuracy and uniform thickness (preferably, thickness variation is 10% or less). For this reason, high quality display is possible.

The light emitting layer 68 may be large enough to run over the insulating layer 64 at the periphery of each opening 65a, 65b. In this case, the light emission color of each light emitting layer located in each opening 65a, 65b is The electrode layers 70 disposed on the openings 65a and 65b may be electrically independent so that each light emitting layer can emit light.
The light emitting element layer 66 has a structure composed of a light emitting layer alone, a structure composed of a hole injection layer and a light emitting layer, a structure provided with a light emitting layer and an electron injection layer, A structure in which a hole transport layer is interposed between the hole injection layer and the light emitting layer, a structure in which an electron transport layer is interposed between the light emitting layer and the electron injection layer, and the like can be employed.

The organic light-emitting device of the present invention is not limited to the above-described embodiment.
FIG. 19 is a partial cross-sectional view showing another embodiment of the organic light-emitting device of the present invention. An organic light emitting device 71 shown in FIG. 19 includes a transparent base 72 and a color filter layer 73 including a red colored layer 73R, a green colored layer 73G, and a blue colored layer 73B in a strip pattern provided on the transparent base 72. And a transparent smoothing layer 75 disposed so as to cover the color filter layer 73, and a strip pattern formed on the transparent smoothing layer 75 in the same manner as the organic light emitting device 31 of the above-described embodiment. A plurality of transparent electrode layers 33, an insulating layer 34 disposed so that a stripe-shaped opening 35 is positioned on each transparent electrode layer 33, and the transparent electrode layer 33 in each opening 35. And a plurality of electrode layers 40 in a strip pattern extending on the light emitting element layer 36 so as to be orthogonal to the transparent electrode layer 33.

  The plurality of transparent electrode layers 33 having the belt-like pattern are positioned on the red colored layer 73R, the green colored layer 73G, and the blue colored layer 73B of the belt-like pattern. The light emitting element layer 36 includes a hole injection layer 37 disposed so as to cover the insulating layer 34 and the transparent electrode layer 33 in each opening 35, and a transparent electrode layer 33 (positive electrode in the opening 35). A plurality of light-emitting layers 38 arranged for each opening 35 so as to cover the hole injection layer 37) and run over the insulating layer 34 at the periphery of the opening 35, and electrons arranged so as to cover them. And an injection layer 39. In the illustrated example, the light emitting layer 38 is a white light emitting layer having a belt-like pattern.

  Such an organic light emitting device 71 includes the color filter layer 73 and the transparent smoothing layer 75, and is the same as the organic light emitting device 31 described above except that the light emitting layer 38 is a white light emitting layer. Therefore, the same member number is attached | subjected to the same member, and description here is abbreviate | omitted. The light emitting element layer 36 has a structure composed of a light emitting layer alone, a structure composed of a hole injection layer and a light emitting layer, a structure composed of a light emitting layer and an electron injection layer, A structure in which a hole transport layer is interposed between the hole injection layer and the light emitting layer, a structure in which an electron transport layer is interposed between the light emitting layer and the electron injection layer, and the like can be employed.

  The color filter layer 73 corrects the color of light from the light emitting element layer 36 or increases the color purity. The red color layer 73R, the green color layer 73G, and the blue color layer 73B constituting the color filter layer 73 can be appropriately selected according to the light emission characteristics of the light emitting element layer 36. For example, pigments, pigment dispersants, It can be formed of a pigment dispersion composition containing a binder resin, a reactive compound, and a solvent. The thickness of such a color filter layer 73 can be appropriately set according to the material of each colored layer, the light emission characteristics of the organic EL element layer, and the like, and can be set, for example, in the range of about 1 to 3 μm.

Further, the transparent smoothing layer 75 eliminates the level difference when the level difference (surface irregularities) exists due to the configuration of the color filter layer 73 or less, thereby achieving flattening and preventing the occurrence of uneven thickness of the light emitting element layer 36. Performs flattening action. Such a transparent smoothing layer 75 can be formed of a transparent (visible light transmittance of 50% or more) resin. Specifically, a photocurable resin or a thermosetting resin having an acrylate-based or methacrylate-based reactive vinyl group can be used. Moreover, as transparent resin, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, A maleic acid resin, a polyamide resin, etc. can be used.
The thickness of such a transparent smoothing layer 75 can be set within a range in which a flattening action can be exhibited in consideration of a material to be used, and can be appropriately set within a range of about 1 to 5 μm, for example.

  FIG. 20 is a partial cross-sectional view showing another embodiment of the organic light-emitting device of the present invention. An organic light emitting device 81 shown in FIG. 20 includes a transparent substrate 82 and a color filter layer 83 including a red colored layer 83R, a green colored layer 83R, and a blue colored layer 83B having a strip-like pattern provided on the transparent substrate 82. And a red-patterned phosphor layer 84R (a layer that converts blue light into red fluorescence) in a band pattern so as to cover the red-colored layer 83R, the green-colored layer 83R, and the blue-colored layer 83B of the color filter layer 83, green A color conversion phosphor layer 84 including a conversion phosphor layer 84G (a layer that converts blue light into green fluorescence) and a blue conversion dummy layer 84B (a layer that transmits blue light as it is) is further provided so as to cover them. The disposed transparent smoothing layer 85 and a plurality of transparent electrode layers 33 in a strip pattern formed on the transparent smoothing layer 85 in the same manner as the organic light emitting device 31 of the above-described embodiment. The insulating layer 34 disposed so that the stripe-shaped opening 35 is positioned on each transparent electrode layer 33, and the light emitting element layer disposed so as to cover the transparent electrode layer 33 in each opening 35. 36, and a plurality of electrode layers 40 in a strip pattern extending on the light emitting element layer 36 so as to be orthogonal to the transparent electrode layer 33.

  The plurality of transparent electrode layers 33 having the band-shaped pattern are located on the red-converted phosphor layer 84R, the green-converted phosphor layer 84G, and the blue-converted dummy layer 84B having the band-shaped pattern. The light emitting element layer 36 includes a hole injection layer 37 disposed so as to cover the insulating layer 34 and the transparent electrode layer 33 in each opening 35, and a transparent electrode layer 33 (positive electrode in the opening 35). A plurality of light-emitting layers 38 arranged for each opening 35 so as to cover the hole injection layer 37) and run over the insulating layer 34 at the periphery of the opening 35, and electrons arranged so as to cover them. And an injection layer 39. In the illustrated example, the light emitting layer 38 is a blue light emitting layer having a belt-like pattern.

  Such an organic light emitting device 81 includes a color filter layer 83, a color conversion phosphor layer 84, and a transparent smoothing layer 85, and the organic light emitting device 31 described above except that the light emitting layer 38 is a blue light emitting layer. It is the same. Therefore, the same member number is attached | subjected to the same member, and description here is abbreviate | omitted. Moreover, the color filter layer 83 and the transparent smoothing layer 85 are the same as the above-mentioned color filter layer 73 and the transparent smoothing layer 75, and description thereof is omitted here. The light emitting element layer 36 has a structure composed of a light emitting layer alone, a structure composed of a hole injection layer and a light emitting layer, a structure composed of a light emitting layer and an electron injection layer, A structure in which a hole transport layer is interposed between the hole injection layer and the light emitting layer, a structure in which an electron transport layer is interposed between the light emitting layer and the electron injection layer, and the like can be employed.

  The red conversion phosphor layer 84R and the green conversion phosphor layer 84G are layers made of a single fluorescent dye or a layer containing a fluorescent dye in a resin. Examples of the fluorescent dye used for the red conversion phosphor layer 84R that converts blue light emission into red fluorescence include cyanine dyes such as 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran, Examples include pyridine dyes such as 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridium-perchlorate, rhodamine dyes such as rhodamine B and rhodamine 6G, and oxazine dyes. It is done. Further, as a fluorescent dye used for the green conversion phosphor layer 84G that converts blue light emission into green fluorescence, 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylquinolidino (9,9a) , 1-gh) coumarin, 3- (2'-benzothiazolyl) -7-diethylaminocoumarin, 3- (2'-benzimidazolyl) -7-N, N-diethylaminocoumarin and other coumarin dyes, basic yellow 51 and other coumarins Examples thereof include dye-based dyes and naphthalimide dyes such as Solvent Yellow 11 and Solvent Yellow 116. Furthermore, various dyes such as direct dyes, acid dyes, basic dyes, and disperse dyes can be used as long as they have fluorescence. The above fluorescent dyes can be used alone or in combination of two or more. When the red conversion phosphor layer 84R and the green conversion phosphor layer 84G contain a fluorescent dye in the resin, the content of the fluorescent dye takes into account the fluorescent dye used, the thickness of the color conversion phosphor layer, and the like. For example, it may be about 0.1 to 1 part by weight with respect to 100 parts by weight of the resin used.

The blue conversion dummy layer 84B transmits the blue light emitted from the light emitting element layer 36 as it is and sends it to the color filter layer 83, and is substantially the same as the red conversion phosphor layer 84R and the green conversion phosphor layer 84G. It can be set as the transparent resin layer of thickness.
When the red conversion phosphor layer 84R and the green conversion phosphor layer 84G contain a fluorescent dye in the resin, the resins include polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxy Transparent (visible light transmittance 50% or more) resin such as methyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin can be used. . When the pattern of the color conversion phosphor layer 84 is formed by a photolithography method, for example, a photocurable resist having a reactive vinyl group such as acrylic acid, methacrylic acid, polyvinyl cinnamate, or ring rubber Resin can be used. Further, these resins can be used for the blue conversion dummy layer 84B described above.

  When the red color conversion phosphor layer 84R and the green color conversion phosphor layer 84G constituting the color conversion phosphor layer 84 are formed of a fluorescent dye alone, for example, it is formed into a band shape by a vacuum deposition method or a sputtering method through a desired pattern mask. Can be formed. When forming a layer containing a fluorescent dye in the resin, for example, a coating solution in which the fluorescent dye and the resin are dispersed or solubilized is applied by a method such as spin coating, roll coating, or cast coating. The red conversion phosphor layer 84R and the green conversion phosphor layer 84G can be formed by a method of forming a film and patterning the film by a photolithography method, a method of pattern printing the above coating liquid by a screen printing method, or the like. The blue conversion dummy layer 84B is formed by applying a desired photosensitive resin paint by a method such as spin coating, roll coating, or cast coating, and patterning this by a photolithography method, or a desired resin coating solution. Can be formed by a method of pattern printing by a screen printing method or the like.

The thickness of the color conversion phosphor layer 84 can exhibit a function in which the red conversion phosphor layer 84R and the green conversion phosphor layer 84G sufficiently absorb the blue light emitted from the light emitting element layer 36 and generate fluorescence. The fluorescent dye to be used, the fluorescent dye concentration, etc. can be set as appropriate, and can be set appropriately, for example, about 10 to 20 μm. The red conversion phosphor layer 84R and the green conversion phosphor The thickness of the layer 84G may be different.
Examples of organic light-emitting materials that emit blue light include fluorescent brighteners such as benzothiazole, benzimidazole, and benzoxazole, metal chelated oxinoid compounds, styrylbenzene compounds, distyrylpyrazine derivatives, and aromatic dimethylidins. A compound etc. can be mentioned.

  Specifically, benzothiazoles such as 2-2 '-(p-phenylenedivinylene) -bishenzothiazole; 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole, 2- [ Benzimidazoles such as 2- (4-carboxyphenyl) vinyl] benzimidazole; 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, Benzoxazole series such as 4,4'-bis (5,7-t-pentyl-2-benzoxazolyl) stilbene, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole And the like.

Examples of the metal chelated oxinoid compound include 8-hydroxyquinoline metal complexes such as tris (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, and bis (benzo [f] -8-quinolinol) zinc. Examples include dilithium epinetridione.
Examples of the styrylbenzene compound include 1,4-bis (2-methylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, Distyrylbenzene, 1,4-bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) benzene, 1,4-bis (2-methylstyryl) -2-methylbenzene, 1,4 -Bis (2-methylstyryl) -2-ethylbenzene and the like can be mentioned.

Examples of the distyrylpyrazine derivative include 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, and 2,5-bis [2- (1-naphthyl). Vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4-biphenyl) vinyl] pyrazine, 2,5-bis [2- (1-pyrenyl) vinyl] pyrazine Etc.
Examples of the aromatic dimethylidin compounds include 1,4-phenylene dimethylidin, 4,4-phenylene dimethylidin, 2,5-xylene dimethylidin, 2,6-naphthylene dimethylidin, , 4-biphenylenedimethylidin, 1,4-p-terephenylenedimethylidin, 9,10-anthracenediyldimethylidin, 4,4'-bis (2,2-di-t-butylphenylvinyl) Biphenyl, 4,4'-bis (2,2-diphenylvinyl) biphenyl, and the like, and derivatives thereof can be mentioned.

Furthermore, as a material of the light emitting layer, a compound represented by the general formula (Rs-Q) 2-AL-OL can be exemplified (in the above formula, AL has 6 to 24 carbon atoms including a benzene ring). A hydrocarbon, OL is a phenylate ligand, Q is a substituted 8-quinolinolato ligand, Rs is a steric bond of two or more substituted 8-quinolinolato ligands to an aluminum atom. Represents an 8-quinolinolate substituent selected to interfere with. Specific examples include bis (2-methyl-8-quinolinolato) (paraphenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum (III), and the like.
In addition, the above-mentioned embodiment is an illustration and this invention is not limited to these. For example, a black matrix may be provided in a portion where the color filter layers 73 and 83 are not formed.

DESCRIPTION OF SYMBOLS 1, 1A, 11 ... Gravure plate 2, 12 ... Cell 3, 13 ... Non-cell part 4, 4a, 4b, 4c ... Picture part 5 ... Frame 6 ... Base plate 6a ... Impression cylinder 7, 7a, 7b, 7c ... Ink supply sections 8, 8a, 8b, 8c ... Doctors 9, 9a, 9b, 9c ... Ink discharge holes 10, 10A ... Printers 14a, 14b, 14c ... Recess 15a ... First area 15b of gravure plate ... Gravure plate 2nd area | region 15c ... 3rd area | region 23 of gravure plate ... Blanket 24 ... Transfer roll 24a ... Plate cylinder 25 ... Blanket cylinder 26 ... Flexographic plates 30, 30R, 30G, 30B ... Ink 31, 61, 71, 81 ... Organic light emitting device 32, 62, 72, 82 ... transparent substrate 33 ... transparent electrode layer 34, 54 ... insulating layer 35, 55 ... opening 36 ... light emitting element layer 37 ... hole injection layer 38, 38R, 38G, 38B, 58R, 58 , 58G ... light-emitting layer 39 ... electron injection layer 40 ... electrode layer 53 ... electrode wiring pattern 100 ... printer 101 ... gravure plate 104, 104a, 104b, 104c ... picture portion

Claims (15)

In a printing machine that prints ink on a substrate,
Frame,
A plate-shaped ink plate disposed on the frame and having cells on its upper surface;
An ink supply unit for supplying ink to the upper surface of the ink plate;
A doctor for filling the cells with ink on the upper surface of the ink plate;
A transfer roll that is provided on the frame so as to be able to run on the frame, receives the ink in the cell in contact with the ink plate, and transfers the ink onto the substrate;
The ink plate is divided into a plurality of regions each having a length corresponding to the circumferential length of the transfer roll along the running direction of the transfer roll, and each region has different types of ink from the ink supply unit. Is supplied,
The cells of one area of the ink plate are shifted in the width direction with respect to the cells of the other area,
A printing machine characterized in that, in each of the areas of the ink plate, an area on the downstream side of the most upstream area is provided with a recess in a portion overlapping with a cell in the upstream area in the width direction. . In a printing machine that prints ink on a substrate,
A roll-shaped ink plate, an ink plate having cells on its outer peripheral surface,
An ink supply unit for supplying ink to the outer peripheral surface of the ink plate;
A doctor for filling the cell with ink on the outer peripheral surface of the ink plate;
A transfer roll that contacts the ink plate and receives the ink in the cell, and transfers the ink onto the substrate,
The ink plate is partitioned into a plurality of regions each having a length corresponding to the circumferential length of the transfer roll along the rotation direction of the ink plate, and different types of ink are supplied to each region from the ink supply unit. Supplied,
The cells of one area of the ink plate are shifted in the width direction with respect to the cells of the other area,
A printing machine characterized in that, in each area of the ink plate, an area on the downstream side of the most upstream area is provided with a concave portion in a portion overlapping with a cell in the upstream area in the width direction. .   The printing press according to claim 1 or 2, wherein an ink discharge hole is provided on a downstream side of the cell in each region of the ink plate.   The printing press according to any one of claims 1 to 3, wherein a separate doctor is provided in each area of the ink plate. The ink plate is arranged in stripes and has a plurality of cells filled with ink from an ink supply unit,
The ratio b / a between the length b in the printing direction and the width a in the direction perpendicular to the printing direction in each cell is 0.6 or more, and the ratio L / S between the cell part length L and the non-cell part length S of each cell. Is 0.8 to 100, the cell part length L is in the range of 10 to 500 μm, the non-cell part length S is in the range of 2 to 500 μm, and the plate depth of each cell is 20 to 200 μm. The printing press according to claim 1 or 2, wherein the printing press is within a range. The ink plate is arranged in a grid and has a plurality of cells filled with ink from an ink supply unit,
The ratio b / a of the maximum length b in the printing direction and the maximum width a in the direction orthogonal to the printing direction in each cell is 0.6 or more, and the total cell area in the film forming region is in the range of 55 to 95%. The printing press according to claim 1 or 2, wherein the non-cell portion length S is in the range of 2 to 500 µm, and the plate depth of each cell is in the range of 20 to 200 µm. The transfer roll has a blanket cylinder and a blanket integrally provided on the peripheral surface of the blanket cylinder,
The printing press according to claim 1 or 2, wherein the blanket is made of a resin film having a surface tension of 35 dyne / cm or more.   The printing press according to claim 7, wherein the resin film has a thickness in a range of 5 to 200 μm.   The printing press according to claim 7 or 8, wherein a cushion layer is interposed between the blanket cylinder and the blanket. The substrate is provided integrally on the surface of the transfer roll,
The printing press according to claim 1 or 2, wherein the ink filled in the cells of the ink plate is directly transferred onto the substrate of a transfer roll. The method of forming the said light emitting layer of the organic light emitting device provided with the electrode which opposes and the said light emitting element layer which has at least a light emitting layer between the said electrodes with the printing machine in any one of Claim 1 thru | or 10. In
Supplying an ink containing at least an organic light emitting material to the ink plate;
Filling the ink plate cells with the ink; and
A step of receiving the ink from the ink plate to the transfer roll,
When the substrate is provided integrally on the surface of the transfer roll, in the step of receiving the ink, the ink filled in the cells of the ink plate is directly on the substrate of the transfer roll. Transferred,
When the base material is provided separately from the transfer roll, the method for forming the light emitting layer further includes a step of transferring the ink of the transfer roll onto the base material. Forming method. The light emitting layer is formed to be arranged at a predetermined pixel pitch in the width direction,
12. The method for forming a light emitting layer according to claim 11, wherein cells in one area of the ink plate are separated from cells in other areas adjacent to one area by a pixel pitch in the width direction.   In the step of supplying ink to the ink plate, the ink supplied to the cells in one area is supplied between the cells in one area and the cells in the upstream area adjacent to the one area. The method for forming a light emitting layer according to claim 11 or 12. The ink is composed of a solvent and a solid content dissolved in the solvent, and has a viscosity at a shear rate of 100 / sec (ink temperature 23 ° C.) in the range of 5 to 200 cP.
The method for forming a light emitting layer according to claim 11, wherein the solvent has a surface tension of 40 dyne / cm or less and a boiling point of 150 to 250 ° C.   The method for forming a light emitting layer according to claim 14, wherein the solid content in the ink is in the range of 1.5 to 4.0 wt%.

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