JP2012238479A - Ink jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a highly reliable ink jet device causing no deterioration in film thicknesses variation between adjacent pixels even when a number of nozzles to which a drive signal is set to be controlled is decreased.SOLUTION: In an ink jet device, one pixel is coated by discharges from a plurality of nozzles, the nozzles are divided into two nozzle groups. A nozzle of a first nozzle group is connected to a control device setting a drive signal for each nozzle, while a nozzle of a second nozzle group is connected to a control device setting a common drive signal.

Description

  The present invention relates to an ink jet device, and for example, relates to a discharge technique for controlling the coating amount of an ink jet device used in a coating process of a light emitting layer of an organic EL panel and ensuring stability and reliability of the device.

  Organic EL displays can be broadly classified into the following two types depending on the method of forming the organic light emitting layer. One is a method of forming an organic light emitting layer by vapor deposition, and is used when the organic light emitting layer is made of a low molecular organic material. The other is a method of forming an organic light emitting layer by a solvent coating method, and is often used not only when the organic light emitting layer is made of a low molecular organic material but also when it is made of a polymer organic material.

  One of the typical means for forming an organic light emitting layer by a solvent coating method is to form an organic light emitting layer by ejecting ink droplets containing an organic light emitting material to pixels of a display substrate using an inkjet device. (For example, refer to Patent Document 1). The ink droplets ejected at this time contain an organic light emitting material and a solvent.

  The ink jet apparatus has an ink jet head having a plurality of nozzles, and ejects ink from the nozzles while controlling the positional relationship between the nozzles of the ink jet head and the substrate (see, for example, Patent Document 2). Patent Document 2 discloses that liquid droplets that have landed on a substrate spread in the same direction to form pixels having a predetermined line width. On the other hand, the pixels of the display substrate from which droplets are ejected are often defined by partition walls called banks. This is because the ejected ink remains in the pixel in a position selective manner. The bank is divided for each pixel.

  The ink jet apparatus includes an ink jet head having a plurality of nozzles, and ejects droplets by driving piezoelectric elements such as piezo elements, and scans the ink jet head or the substrate to eject droplets to pixels on the substrate. Thus, an organic light emitting layer is formed. However, even if the same drive voltage and drive waveform are applied to each nozzle, the discharge amount of the discharged ink is not the same and a difference occurs in the discharge amount. Therefore, since the amount of ink applied to each pixel is different, a difference occurs in the film thickness of the organic light emitting layer. As a result, display unevenness occurs when the display is lit.

  As a method of applying the same amount of ink to each pixel, a method of controlling the droplet discharge amount for each nozzle is disclosed. (See Patent Document 3).

Patent Document 3 will be described with reference to FIG. FIG. 13 is a circuit configuration diagram of a conventional droplet discharge head and a drive circuit board. Reference numeral 30 denotes a drive circuit board. The drive circuit board 30 is for controlling the amount of ink discharged from each nozzle of the inkjet head. As shown in FIG. 13, the drive circuit board 30 includes an interface 31, a drawing data memory 32, an address conversion circuit 33, a first drive waveform memory 34, a second drive waveform memory 35, a first D / A converter 36, A second D / A converter 37, a third D / A converter 38, and a fourth D / A converter 39 are provided. The inkjet head 100 includes a COM selection circuit 40, a switching circuit 50, and a piezoelectric element group 60 including piezoelectric elements PZ _{1 to} PZ ₁₈₀ . The number of nozzles of the ink jet head controlled by the drive circuit board 30 is 180 nozzles. With this method, the droplet discharge amount of each nozzle can be accurately controlled.

JP 2004-362818 A JP 2003-266669 A JP 2008-191447 A

  However, in the conventional example shown in Patent Document 3, there is no particular problem when the substrate on which the droplets are discharged is small. However, when the substrate is enlarged, the number of nozzles to be controlled increases, and driving is performed for each nozzle. The circuit board for controlling the waveform becomes complicated and causes a problem that reliability is lowered. For example, in a 20-inch panel, the substrate size is 370 mm × 470 mm, and if the nozzle-to-nozzle pitch is 1200 dpi (dot per inch), the pitch is 21.1667 mm, which requires about 23,000 nozzles. For a 40-inch panel, the dimensions are 680 mm × 880 mm. In the future, it is expected that 1300 mm × 1500 mm and 2200 mm × 2500 mm substrates will also be used in the display industry in order to reduce the cost of a single substrate in order to reduce costs.

  The present invention has been made in consideration of the problems that occur when an organic light emitting layer is formed by the conventional ink jet device, and provides a highly reliable ink jet device without complicating the drive circuit board. It is intended.

  A first inkjet device according to the present invention is an inkjet device that applies ink to pixels provided on a substrate by ejecting ink from a nozzle, and the nozzle is configured to use one pixel as a first nozzle group. The nozzles of the first nozzle group are connected to a control device that sets a drive signal for each nozzle. The nozzles of the two nozzle groups are connected to a control device that sets a common drive signal, so that the drive circuit board is not complicated and the reliability is high, and the cost of the drive circuit board can be suppressed.

  In the second inkjet device of the present invention, the number of the nozzles of the first nozzle group in the first aspect is smaller than the number of nozzles that can be landed on the pixels.

  In the third inkjet apparatus according to the present invention, the nozzles of the first nozzle group in the second aspect are only one nozzle among the nozzles with respect to the pixels.

  In the fourth ink jet apparatus according to the present invention, the nozzles of the first nozzle group in the second aspect include a nozzle for complementing when non-ejection occurs, and The nozzle is a position where the nozzle is applied adjacent to the landing position where the nozzle is applied.

  In the fifth inkjet device according to the present invention, the nozzle for complementation in the fourth aspect is disposed at a position where the nozzle is applied on one side or both sides with respect to the landing position where the nozzle is applied.

  In the sixth inkjet device according to the present invention, the complementary nozzle arranged on the one side in the fifth aspect is a nozzle that lands at a position far from the center of the pixel.

  According to the present invention, when applying to the pixels on the substrate, the application amount of each pixel can be made constant even if the number of nozzles to be controlled is reduced. A high ink jet apparatus can be provided.

The top view of the board | substrate which should apply | coat the ink in the manufacturing method of the organic electroluminescent display of Embodiment 1 which concerns on this invention It is an expanded sectional view of the board | substrate in the manufacturing method of the organic electroluminescent display of Embodiment 1, and sectional drawing by the AA line of the board | substrate shown in FIG. The figure which shows the positional relationship of the inkjet head of the inkjet apparatus used in the manufacturing method of the organic electroluminescent display of Embodiment 1, and a board | substrate. The figure which shows arrangement | positioning of the inkjet head in the inkjet apparatus used in the manufacturing method of the organic electroluminescent display of Embodiment 1 thru | or 4. The enlarged view of the nozzle row | line | column of the inkjet head in the inkjet apparatus used in the manufacturing method of the organic electroluminescent display of Embodiment 1-4 In the manufacturing method of the organic electroluminescent display according to the first embodiment, the arrangement of the nozzle row 11 for setting and controlling the common drive signal with the nozzle row 10 for setting and controlling the drive signal for each nozzle of the inkjet head The figure which shows the application position at the time of the landing of the ink discharged from each nozzle when a droplet is apply | coated to a pixel in the manufacturing method of the organic electroluminescent display of Embodiment 1. FIG. Sectional drawing which shows schematic layer structure of the organic electroluminescent display which has the organic light emitting layer formed in the manufacturing method of the organic electroluminescent display of Embodiment 1 using the inkjet apparatus. The figure which shows the flowchart which shows the process in the manufacturing method of the organic electroluminescent display of Embodiment 1. The figure which shows the application position at the time of the landing of the ink discharged from each nozzle when a droplet is apply | coated to the pixel 4 in the manufacturing method of the organic electroluminescent display of Embodiment 2 which concerns on this invention. The figure which shows the application position at the time of the landing of the ink discharged from each nozzle when a droplet is apply | coated to the pixel 4 in the manufacturing method of the organic electroluminescent display of Embodiment 3 which concerns on this invention. The figure which shows the application position at the time of the landing of the ink discharged from each nozzle when a droplet is apply | coated to the pixel 4 in the manufacturing method of the organic electroluminescent display of Embodiment 4 which concerns on this invention. The figure which shows the drive circuit board for controlling the discharge amount of each nozzle of the conventional inkjet head

  Hereinafter, an ink jet apparatus according to a preferred embodiment of the present invention will be described.

  In the following description, a method for manufacturing an organic electroluminescent display (hereinafter, abbreviated as an organic EL display) having an organic light emitting film will be described as an example with reference to the accompanying drawings. In addition, the ink application method and the ink jet apparatus of the present invention are not limited to the organic EL display manufacturing method, and can be applied to displays of various electronic devices, for example, color filters of liquid crystal display devices.

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

(Embodiment 1)
FIG. 1 is a plan view of a substrate on which an ink containing an organic light emitting material is to be applied, as viewed from above, in the method for manufacturing an organic EL display according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the substrate shown in FIG. 1, and FIG. 2 is a cross-sectional view of the substrate 1 shown in FIG.

  As shown in FIGS. 1 and 2, the substrate 1 has a bank 3 for defining pixels 4 on a base substrate 2. On the base substrate 2 on which the banks 3 are formed, elements necessary for an organic EL display such as a reflective anode and a hole injection layer are formed although not shown. The cross-sectional shape of the bank 3 may be a forward taper type as shown in FIG. 2 or may be a reverse taper type with a narrow skirt.

  As the material of the bank 3 in the first embodiment, any material can be used as long as it is an insulating material, and it is an insulating resin (for example, polyimide resin) having heat resistance and resistance to solvents. preferable. Further, the bank 3 is added with fluorine to provide water repellency. As a method for forming the bank 3, a photolithography technique or the like is used, which is formed by patterning. For example, after applying the bank material, a desired shape is formed on the base substrate 2 by baking, mask exposure, development, and the like.

  Ink 9 is ejected and applied to the area regulated and partitioned by the bank 3. Since the bank 3 has water repellency, as will be described later, even when the ink 9 is applied to the pixels 4, even if it rises between the banks 3, it is reliably held by the bank 3 and is securely stored between the banks 3.

  As shown in the plan view of FIG. 1, the bank 3 formed on the base substrate 2 includes a plurality of pixels 4 for R (red), G (green), and B (blue), Each is arranged in a line.

  The width of the bank 3 between the pixels 4 is 60 μm. The R, G, B banks 3 formed as described above are repeatedly formed on the substrate 1 at a pitch of 350 μm.

  FIG. 3 is a diagram showing a positional relationship between the three inkjet line heads 5R, 5G, and 5B for R, G, and B in the inkjet apparatus of Embodiment 1 and the substrate 1 shown in FIG. In a scanning operation to be described later, the row region surrounded by the bank 3 is arranged to be a landing position (so-called landing point) of the ink 9. In FIG. 3, the arrow indicated by the symbol X is the scanning direction of the inkjet head 6.

  FIG. 4 is a diagram showing a substrate facing surface in the inkjet line head 5 (5R, 5G, 5B). The inkjet line heads 5R, 5G, and 5B have a configuration in which inkjet heads 6 arranged obliquely are arranged. Since the three inkjet heads 6R, 6G, and 6B for R, G, and B have the same configuration, they will be described as the inkjet line head 5 in the following description.

  Reference numeral 7 denotes a nozzle row. The nozzle row 7 is adjacent to each other by 2 lines, and there are a total of 8 lines. The straight lines A, B, and C are straight lines for explaining that the nozzle rows 7 are arranged obliquely with respect to the scanning direction so that application can be performed on the base substrate 2 at equal intervals.

  FIG. 5 shows an enlarged view of a part of the nozzle row 7, and the nozzles 8 are arranged in a line.

  As shown in FIG. 4, in the inkjet line head 5, a plurality of nozzles 8 are formed on the surface facing the substrate 1. In the inkjet line head 5, a nozzle row 7 in which a plurality of nozzles 8 are arranged in a line with respect to the scanning direction (the arrow X direction in FIG. 4) with respect to the substrate 1 is arranged obliquely. A plurality of columns having 8 are arranged in parallel with each other.

  In the inkjet line head 5, the nozzle row 7 in which the plurality of nozzles 8 are arranged in a line is arranged obliquely with respect to the scanning direction because the ink 9 is applied in the row region surrounded by the bank 3. This is because the pitch between the nozzles 8 is short, for example, about 20 μm so that the inks 9 ejected from the nozzles 8 are connected to each other at the landing position. In this manner, by arranging the nozzle rows 7 of the plurality of nozzles 8 obliquely with respect to the scanning direction, it is possible to set the nozzle pitch interval to a desired distance.

  FIG. 6 is an arrangement diagram of the nozzle row 11 for setting and controlling the common drive signal with the nozzle row 10 for setting and controlling the drive signal for each nozzle in the nozzles 8 in the nozzle row 7 of the inkjet head 6. The nozzle row 10 that is set and controlled for each nozzle is indicated by a black circle, and the nozzle row 11 that is set and controlled by a common drive signal is indicated by a white circle. Of the nozzle array 7, only two nozzle groups are set and controlled for each nozzle.

  FIG. 7 shows a coating position when ink ejected from each nozzle is landed when droplets are coated on the pixels 4. In FIG. 7, black circles indicate the landing positions of the ink 9 ejected by controlling the drive signal for each nozzle, and white circles indicate the landing positions of the ink 9 ejected from the nozzles controlled by the common drive signal. . An arrow indicated by a symbol X indicates the scanning direction of the inkjet line head 5.

  FIG. 7 shows a case where droplets are applied to the pixels 4. In this embodiment, the size per pixel is 60 μm × 170 μm, and 26 drops are applied. The higher the definition, the smaller the area that is applied. The pitch of the application position at the time of landing is about 20 μm. The number of droplets applied to the pixels 4 is set to have a desired film thickness. The maximum number of droplets to be applied in the longitudinal direction of the pixel 4 is 9 μm in the longitudinal direction from 170/20 = 8.5 since the pitch between nozzles is 20 μm when the longitudinal dimension is 170 μm. It becomes.

  When 26 drops are applied to the pixel 4, for example, 9 drops, 8 drops, and 9 drops are applied in a line. In the present embodiment, an example in which coating is performed for three lines every 5.29 μm is shown. It is preferable to determine which line and position to apply in consideration of the uniformity of the film thickness. The coating pitch in the scanning direction X is 5.29 μm when applied at 4800 dpi, and when the length of the pixel 4 in the scanning direction is 60 μm, 60 μm / 5.29 μm = 11.4 to 11 lines. Application is possible. However, in order to prevent color mixing and the like, the coating is performed as close to the center of the pixel 4 as possible. Therefore, it is applied at a distance of 5 lines by applying 3 lines or skipping 1 line.

  Hereinafter, a specific coating method executed in the method for manufacturing the organic EL display according to Embodiment 1 will be described.

  The ejection amount of the ink 9 from the nozzle 8 in the inkjet line head 5 is measured in advance. Measurement methods include, for example, a gravimetric method and an evaluation method using a laser microscope. The weight method is a method in which the ink 9 is ejected from a single nozzle 8 for a certain period of time, and the weight of the ink is measured with a high-precision scale such as an chemical balance. Since the number of times of ejection in a certain time is known from the drive frequency of the inkjet head 6, the amount of ejection per time is known. With the gravimetric method, the ink discharge amount itself is known. In the method using a laser microscope, for example, 50 drops of ink 9 are ejected from one nozzle 8, the ink 9 is dried, the volume after drying is measured, and the volume of one nozzle 8 is divided by the number of ejected droplets. And the ejection amount is calculated in terms of the ink 9 before drying.

  In the method of coating the substrate 1 by the inkjet line head 5, ink is ejected from the nozzles 8 while the inkjet line head 5 is scanned with respect to the substrate 1. The scanning direction at this time is the same as the direction orthogonal to the bank 3 including the R, G, B pixels 4 arranged in a line on the substrate 1 as shown in FIG. The inkjet line head 5 (5R, 5G, 5B) performs a coating operation on the substrate 1, assuming that a predetermined ink 9 is ejected from the nozzle 8 to each row region for R, G, B.

  Hereinafter, the process of the nozzle control method in the present embodiment will be described. As shown in FIGS. 3 and 7, the discharge amount of each nozzle is calculated in advance because the position of the nozzle 8 to be applied to the pixel 4 is known in advance. Next, when it is predicted that the total amount of ejection will exceed the desired amount, the drive signal is controlled for each nozzle represented by a black circle to reduce the ink ejection amount of the ejected nozzle and bring it closer to the desired value. When the total discharge amount is predicted to be smaller than the desired amount, the drive signal is controlled for each nozzle represented by a black circle to increase the ink discharge amount of the nozzle to be discharged and approach the desired value.

  For example, when the target discharge amount to be discharged from the nozzle 8 is 7 pl, when 26 drops are applied to the pixel 4, 182 pl is the target of the discharge amount. When calculated from the actual discharge amount of the nozzle 8, when the discharge amount entering the pixel 4 is small, for example, in the case of 172 pl, another 10 pl may be added. The nozzle 8 in the nozzle array 10 that controls by setting a drive signal for each nozzle that enters the pixel 4 discharges three times for each of the two nozzles, so the drive signal is set from 10 ÷ 9 = 1.11 pl. It can be seen that the discharge amount of the nozzles 8 in the nozzle row 7 to be controlled should be 7 + 1.11 = 8.11 pl. Conversely, when the discharge amount applied to the pixel 4 is larger than 182 pl, the discharge amount of the nozzle 8 in the nozzle row 10 controlled by setting a drive signal for each nozzle entering the pixel 4 is adjusted. It will be good. For example, if the discharge amount to be applied in the pixel 4 is 192 pl, it is 10 pl, and therefore 10 ÷ 9 = 1.11 pl. It can be seen that -1.11 = 5.89 pl should be discharged. The ejection amount of the nozzles 8 in the nozzle row 10 that is controlled by setting a drive signal for each nozzle corresponding to each pixel in the line direction of the inkjet line head 5 (5R, 5G, 5B) is adjusted by the above method.

  In the present embodiment, a flexible board (not shown) that relays a signal of a control board (not shown) for driving the nozzles 8 of the inkjet head 6 is soldered or ACF (anisotropic conductive particles). It is joined. There are two nozzle rows 10 out of eight rows that are controlled by setting a drive signal for each nozzle, and there is an advantage that the configuration of the flexible substrate to which the circuit is connected becomes simple and the flexible substrate can be easily mounted.

  As described above, in the ink jet apparatus according to the first embodiment of the present invention, when ink 9 is ejected to the pixels 4 defined and defined by the banks 3 on the substrate 1, the ink 9 is ejected into the pixels 4. Even if the number of nozzles to be controlled is reduced without controlling all the nozzles 8 by controlling the discharge amount of the nozzles 8 in the nozzle row 10 which is controlled by setting a drive signal for each nozzle, the application of each pixel Since the amount can be made constant, highly reliable coating can be realized without complicating the drive circuit board. Moreover, the cost increase of the drive circuit board can be suppressed.

  In addition, there is an advantage that the configuration of the flexible substrate to which the circuit is connected becomes simple and the flexible substrate can be easily mounted.

  In the ink jet apparatus of the first embodiment, the application speed from the nozzle 8 is a distance of 5.291667 μm in the scanning direction because the DPI (dot per inch) in the scanning direction is 4800 dpi. The application process for the substrate 1 by the ink jet apparatus is configured to be performed in one scanning operation. The order of applying the R, G, B ink 9 is not particularly limited. In addition, it is preferable that the thickness of the organic light emitting layer of R, G, B formed after coating is about 50 to 100 nm (for example, 70 nm).

  The thickness after coating is measured by vacuum drying after the coating process to form an organic light emitting film. Drying conditions are as follows: after standing for 1 minute after application, putting in a drying furnace, pulling a vacuum to 1 Pa in 5 minutes, and then drying for 20 minutes with the temperature kept at 40 ° C. and the degree of vacuum kept at 1 Pa. .

<Example>
In the first embodiment, the ejection amount of the ink 9 of the nozzle 8 in the inkjet line head 5 is measured in advance. A gravimetric method was used as a measurement method. The driving frequency of the nozzle 8 was 10 kHz.

  In the method of coating the substrate 1 by the inkjet line head 5, ink is ejected from the nozzles 8 while the inkjet line head 5 is scanned with respect to the substrate 1. The scanning direction at this time is the same as the direction orthogonal to the bank 3 including the R, G, B pixels 4 arranged in a line on the substrate 1 as shown in FIG. The inkjet line head 5 (5R, 5G, 5B) performs a coating operation on the substrate 1, assuming that a predetermined ink 9 is ejected from the nozzle 8 to each row region for R, G, B. As the size of the substrate 1, a substrate having a size of 370 mm × 470 mm was used.

  As shown in FIGS. 3 and 7, the discharge amount of each nozzle is calculated in advance because the position of the nozzle 8 applied to the pixel 4 is known in advance. For example, when the target discharge amount to be discharged from the nozzle 8 is 7 pl, when 26 drops are applied in the pixel 4, the target is 182 pl. The discharge amount of the nozzle 8 in the nozzle row 10 which is controlled by setting a drive signal for each nozzle entering the pixel 4 is adjusted, and the discharge amount discharged into the pixel 4 is controlled to be 182 pl.

  As a result of applying the ink 9 and vacuum drying to form an organic light-emitting film by the above method and measuring the film thickness, the variation between adjacent pixels is 2.5. By controlling the discharge amount of the nozzle with respect to%, the variation was improved by 1.2%.

  In the ink jet apparatus of Embodiment 1, the organic light emitting material contained in the ink 9 is preferably a polymer light emitting material. Examples of the polymer light emitting material include polyphenylene vinylene (PPV) and Derivatives thereof, polyacetylene and derivatives thereof, polyphenylene and derivatives thereof, polyparaphenylene ethylene and derivatives thereof, poly 3-hexylthiophene and derivatives thereof (P3HT) Derivatives, polyfluorene (PF), and derivatives thereof are included. The ink viscosity is about 10 mPa · s.

  FIG. 8 shows an example of an organic EL display having an organic light emitting layer and the like formed using the ink jet apparatus according to the first embodiment, and is a cross-sectional view schematically showing a layer structure in the organic EL display. The relative film thickness and shape of each layer shown in FIG. 8 do not indicate the actual film thickness and shape, but are described in an easy-to-understand manner for explanation.

  In the organic EL display shown in FIG. 8, the reflective anode 15 and the hole injection layer 16 are formed on the planarizing film 14 on the base substrate, and the bank 3 is formed on the hole injection layer 16. Yes. As described above, the interlayer (IL layer) 17 and the organic light emitting layer 18 are formed in the region partitioned by the bank 3. The reflective anode 15 is separately formed corresponding to the pixel 4 shown in FIG. 1, and serves as a light emitting portion of the display.

  The ink jet device according to the first embodiment is used in the coating process in the formation of the organic light emitting layer 18, and the ink jet apparatus having the same configuration is used in the coating process in the formation of the interlayer layer (IL layer) 17.

  As shown in FIG. 8, in the organic EL display, an electron transport layer 19, a cathode 21, a sealing layer 21, and a resin layer 22 are formed so as to cover the organic light emitting layer 18 and the bank 3. An organic EL display is configured by providing a substrate 23, a polarizing plate 24, and the like on the resin layer 22.

  The organic EL display configured as described above is manufactured as shown in the process flowchart of FIG. That is, planarization film formation → reflection anode formation → hole injection layer formation → bank formation → interlayer layer (hereinafter referred to as IL layer) formation → organic light emitting layer formation → electron transport layer formation → cathode formation → sealing layer formation → It is manufactured in the order of resin layer formation. In this manufacturing process, the IL layer and the organic light emitting layer are generated by applying a predetermined material using the ink jet apparatus described in the first embodiment.

  As described above, in the method of manufacturing the organic EL display according to the first embodiment, when the ink jet apparatus ejects the ink 9 to the pixels 4 defined and defined by the banks 3 on the substrate 1, Even if the number of nozzles to be controlled is reduced without controlling all the nozzles 8 by controlling the discharge amount of the nozzles 8 in the nozzle row 10 which is controlled by setting a drive signal for each nozzle entering, Since the coating amount can be made constant, the drive circuit board can be made highly reliable and the cost of the drive circuit board can be suppressed without complicating the drive circuit board.

  According to the manufacturing method of the organic EL display of Embodiment 1, since the uniformity of the film thickness between the pixels 4 can be ensured, a high-quality organic EL display free from luminance unevenness can be provided.

(Embodiment 2)
Hereinafter, an ink jet apparatus according to a second embodiment of the present invention will be described with reference to the drawings.

  In the ink jet apparatus of the second embodiment, the configuration of the main part is the same as that of the first embodiment. The difference from the ink jet apparatus according to the first embodiment is that the nozzle 8 that discharges into the pixel 4 has one nozzle that is controlled by setting a drive signal. In the description of the second embodiment, components having the same configurations as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted in the second embodiment by using the description of the first embodiment. To do.

  FIG. 10 shows an application position when ink ejected from each nozzle is landed when a droplet is applied to the pixel 4. In FIG. 10, black circles indicate the landing positions of the ink 9 ejected by controlling the drive signal for each nozzle, and white circles indicate the landing positions of the ink 9 ejected from the nozzles controlled by the common drive signal. . An arrow indicated by a symbol X indicates the scanning direction of the inkjet line head 5. FIG. 10 shows a case where 26 drops are applied to the pixels 4 as in the first embodiment.

  Hereinafter, a specific coating method executed in the method for manufacturing an organic EL display in the second embodiment will be described.

  The ejection amount of the ink 9 from the nozzle 8 in the inkjet line head 5 is measured in advance as in the first embodiment. In the method of coating the substrate 1 by the inkjet line head 5, ink is ejected from the nozzles 8 while the inkjet line head 5 is scanned with respect to the substrate 1.

  The scanning direction at this time is the same as the direction orthogonal to the bank 3 including the R, G, B pixels 4 arranged in a line on the substrate 1 as shown in FIG. The inkjet line head 5 (5R, 5G, 5B) performs a coating operation on the substrate 1, assuming that a predetermined ink 9 is ejected from the nozzle 8 to each row region for R, G, B. As shown in FIGS. 3 and 10, the discharge amount of each nozzle is calculated in advance because the position of the nozzle 8 to be applied to the pixel 4 is known in advance.

  For example, when the target discharge amount to be discharged from the nozzle 8 is 7 pl, when 26 drops are applied to the pixel 4, 182 pl is the target of the discharge amount. When calculated from the actual discharge amount of the nozzle 8, when the discharge amount entering the pixel 4 is small, for example, in the case of 172 pl, another 10 pl may be added. Since the nozzle 8 in the nozzle array 10 that controls by setting a drive signal for each nozzle that enters the pixel 4 discharges one nozzle three times, the drive signal is set from 10 ÷ 3 = 3.33 pl. It can be seen that the discharge amount of the nozzles 8 in the nozzle row 7 to be controlled may be 7 + 3.33 = 10.33 pl.

  Conversely, when the discharge amount applied to the pixel 4 is larger than 182 pl, the discharge amount of the nozzle 8 in the nozzle row 10 controlled by setting a drive signal for each nozzle entering the pixel 4 is adjusted. It will be good. For example, if the discharge amount to be applied in the pixel 4 is 192 pl, it is 10 pl, so 10 ÷ 3 = 3.33 pl, and the discharge amount of the nozzles 8 in the nozzle row 7 controlled by setting the drive signal is 7 -3.33 = 3.67 pl should be discharged.

  The ejection amount of the nozzles 8 in the nozzle row 10 that is controlled by setting a drive signal for each nozzle corresponding to each pixel in the line direction of the inkjet line head 5 (5R, 5G, 5B) is adjusted by the above method.

  As described above, in the ink jet apparatus according to the second embodiment of the present invention, when ink 9 is ejected to the pixels 4 defined and defined by the banks 3 on the substrate 1, the ink 9 is ejected into the pixels 4. By setting the drive signal to the nozzle 8 and controlling it to one nozzle, it is possible to make the application amount of each pixel constant even if the number of nozzles to be controlled is reduced without controlling all the nozzles 8. Therefore, highly reliable coating can be realized without complicating the drive circuit board. Moreover, the cost increase of the drive circuit board can be suppressed.

  According to the manufacturing method of the organic EL display of Embodiment 2, since the uniformity of the film thickness between the pixels 4 can be ensured, a high-quality organic EL display having no luminance unevenness can be provided.

(Embodiment 3)
Hereinafter, an ink jet apparatus according to a third embodiment of the present invention will be described with reference to the drawings.

  In the ink jet device of the third embodiment, the configuration of the main part is the same as that of the second embodiment. The difference from the ink jet apparatus of the second embodiment is that, in the nozzle 8 that discharges into the pixel 4, the nozzle adjacent to the nozzle that is controlled by setting the drive signal can also be controlled by setting the drive signal. In the first embodiment, since every four nozzles 8 are discharged from the nozzle arrangement, there is no adjacent nozzle.

  Since the second embodiment also has only one nozzle 8, there is no adjacent nozzle. In the description of the third embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted in the third embodiment by using the description of the first embodiment. To do.

  FIG. 11 shows an application position at the time of landing of ink ejected from each nozzle when a droplet is applied to the pixel 4. In FIG. 11, black circles indicate the landing positions of the ink 9 ejected by controlling the drive signal for each nozzle, and white circles indicate the landing positions of the ink 9 ejected from the nozzles controlled by the common drive signal. . The hatched circle is the landing position of the complementary nozzle when the nozzle 8 that discharges by controlling the drive signal to land at the position of the black circle does not discharge.

  The landing position of the complementary nozzle when the nozzle 8 fails to discharge (the landing position 26 of the complementary nozzle when the nozzle that discharges by controlling the drive signal does not discharge) is farther from the center of the pixel 4. Deploy. This is because the uniformity of the pixel is better when the landing position of the nozzle 8 ejected by controlling the drive signal for each original nozzle is closer to the center of the pixel 4. In the first and second embodiments, there are no adjacent nozzles, and therefore no complementary nozzles are provided.

  An arrow indicated by a symbol X indicates the scanning direction of the inkjet line head 5. FIG. 11 shows a case where 26 drops are applied to the pixel 4 as in the first embodiment.

  Hereinafter, a specific coating method executed in the method for manufacturing an organic EL display in the second embodiment will be described.

  The ejection amount of the ink 9 from the nozzle 8 in the inkjet line head 5 is measured in advance as in the first embodiment. In the method of coating the substrate 1 by the inkjet line head 5, ink is ejected from the nozzles 8 while the inkjet line head 5 is scanned with respect to the substrate 1. The scanning direction at this time is the same as the direction orthogonal to the bank 3 including the R, G, B pixels 4 arranged in a line on the substrate 1 as shown in FIG. The inkjet line head 5 (5R, 5G, 5B) performs a coating operation on the substrate 1, assuming that a predetermined ink 9 is ejected from the nozzle 8 to each row region for R, G, B.

  As shown in FIGS. 3 and 11, the discharge amount of each nozzle is calculated in advance because the position of the nozzle 8 to be applied to the pixel 4 is known in advance. For example, when the target discharge amount to be discharged from the nozzle 8 is 7 pl, when 26 drops are applied to the pixel 4, 182 pl is the target of the discharge amount. If the nozzle 8 that discharges by controlling the drive signal to land at the position of the black circle does not discharge, the remaining discharge obtained by subtracting the amount of ink 9 discharged from the nozzle controlled by the common drive signal from 182pl By supplementing the amount of ink 9 with a complementary nozzle, 182 pl can be supplied to the pixel 4.

  As described above, in the ink jet apparatus according to the third embodiment of the present invention, when ink 9 is ejected to the pixels 4 defined and defined by the banks 3 on the substrate 1, the ink 9 is ejected into the pixels 4. Even if the nozzle controlled by setting a drive signal to the nozzle 8 is not ejected, the application amount of each pixel can be made constant by the complementary nozzle arranged adjacently. As a result, the number of nozzles ejected by controlling the drive signal can be reduced instead of the total number, so that highly reliable coating can be realized without complicating the drive circuit board. Moreover, the cost increase of the drive circuit board can be suppressed.

  According to the manufacturing method of the organic EL display of Embodiment 3, since the uniformity of the film thickness between the pixels 4 can be ensured, a high-quality organic EL display free from luminance unevenness can be provided.

(Embodiment 4)
Hereinafter, an ink jet apparatus according to a fourth embodiment of the present invention will be described with reference to the drawings.

  In the ink jet device according to the fourth embodiment, the configuration of the main part is the same as that of the third embodiment. The difference from the ink jet apparatus according to the third embodiment is that, in the nozzles 8 that discharge into the pixels 4, there are nozzles that complement when the nozzles 8 that are set and controlled by the drive signal are not ejected. In the description of the fourth embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted in the fourth embodiment by using the description of the first embodiment. To do.

  FIG. 12 shows an application position at the time of landing of the ink ejected from each nozzle when a droplet is applied to the pixel 4. In FIG. 12, black circles indicate the landing positions of the ink 9 ejected by controlling the drive signal for each nozzle, and white circles indicate the landing positions of the ink 9 ejected from the nozzles controlled by the common drive signal. The hatched circle is the landing position of the complementary nozzle when the nozzle 8 that discharges by controlling the drive signal to land at the position of the black circle does not discharge. This represents a nozzle that lands on both sides of the landing position of the ejected ink 9 by controlling the drive signal for each nozzle.

  An arrow indicated by a symbol X indicates the scanning direction of the inkjet line head 5. FIG. 12 shows a case where 26 drops are applied to the pixel 4 as in the first embodiment.

  Hereinafter, a specific coating method executed in the method for manufacturing an organic EL display in the second embodiment will be described.

  The ejection amount of the ink 9 from the nozzle 8 in the inkjet line head 5 is measured in advance as in the first embodiment. In the method of coating the substrate 1 by the inkjet line head 5, ink is ejected from the nozzles 8 while the inkjet line head 5 is scanned with respect to the substrate 1.

  The scanning direction at this time is the same as the direction orthogonal to the bank 3 including the R, G, B pixels 4 arranged in a line on the substrate 1 as shown in FIG. The inkjet line head 5 (5R, 5G, 5B) performs a coating operation on the substrate 1, assuming that a predetermined ink 9 is ejected from the nozzle 8 to each row region for R, G, B. As shown in FIGS. 3 and 12, the discharge amount of each nozzle is calculated in advance because the position of the nozzle 8 to be applied to the pixel 4 is known in advance. For example, when the target discharge amount to be discharged from the nozzle 8 is 7 pl, when 26 drops are applied to the pixel 4, 182 pl is the target of the discharge amount. If the nozzle 8 that discharges by controlling the drive signal to land at the position of the black circle does not discharge, the remaining discharge obtained by subtracting the amount of ink 9 discharged from the nozzle controlled by the common drive signal from 182pl By supplementing the amount of ink 9 with a complementary nozzle, 182 pl can be supplied to the pixel 4.

  As described above, in the ink jet apparatus according to the third embodiment of the present invention, when ink 9 is ejected to the pixels 4 defined and defined by the banks 3 on the substrate 1, the ink 9 is ejected into the pixels 4. Even if a nozzle controlled by setting a drive signal to the nozzle 8 is not ejected, the application amount of each pixel can be made constant by the complementary nozzle arranged adjacently. As a result, the number of nozzles ejected by controlling the drive signal can be reduced instead of the total number, so that highly reliable coating can be realized without complicating the drive circuit board.

  Moreover, the cost increase of the drive circuit board can be suppressed.

  According to the manufacturing method of the organic EL display of Embodiment 3, since the uniformity of the film thickness between the pixels 4 can be ensured, a high-quality organic EL display free from luminance unevenness can be provided.

<Other embodiments>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described first to fourth embodiments, and various modifications can be made.

  For example, in the first to fourth embodiments, the case where R, G, and B pixels are applied to a single substrate has been described. However, in order to make multiple faces, a large number of pixels are formed in the substrate. This pattern can be handled in the same manner in consideration of the case where only the pixel portion is applied.

  In the example of the first embodiment, the normal ejection frequency of the ink ejected from the nozzles has been described as 10 kHz. However, the frequency is not particularly limited to this, and according to the specifications of the organic EL display to be manufactured, etc. Set as appropriate.

  In the first to fourth embodiments, a row in which a plurality of nozzles are arranged in a line in the inkjet head is arranged obliquely with respect to the scanning direction, and the pitch between the nozzles in the direction orthogonal to the scanning direction is set. It was designed as about 20 μm (for example, 21.16666 μm). This is because the ink ejected from the nozzles is connected to each other at the landing position. Therefore, the pitch between the nozzles in the direction orthogonal to the scanning direction is preferably in the range of 10 μm to 50 μm, but is not particularly limited.

  In the first to fourth embodiments, the amount of ink discharged from the nozzle per droplet is 7 pl, but it is preferably in the range of 1 pl to 15 pl, and is not particularly limited. .

  In the example of Embodiment 1, the ink having a viscosity of 10 mPa · s was used. However, in the present invention, the viscosity of the ink is not limited to this value, and is preferably in the range of about 5 to 20 mPa · s. There is no particular limitation.

  The ink application method and the ink jet apparatus of the present invention have an effect that the application amount of each pixel can be made constant even if the number of nozzles to be controlled is reduced, and the ink jet used for the application process of the light emitting layer of the organic EL panel. The present invention can be widely applied to an apparatus, an ink jet apparatus used for printer recording processes and color filter manufacturing.

1, 23 Substrate 2 Base substrate 4 Pixel 5, 5R, 5G, 5B Inkjet line head 6, 6R, 6G, 6B, 100 Inkjet head 7 Nozzle array 8 Nozzle 9 Ink 10 Nozzle for setting and controlling drive signal for each nozzle Row 11 Nozzle row controlled by setting common drive signal 12 Landing position of ink 9 ejected by controlling drive signal for each nozzle 13 Landing of ink 9 ejected from nozzle controlled by common drive signal Position 26 Landing position of the complementary nozzle when the nozzle that discharges by controlling the drive signal becomes non-ejection

Claims (6)

In an inkjet apparatus that has a plurality of nozzles and applies ink from the nozzles,
Among the plurality of nozzles, the nozzles of the first nozzle group are connected to a control device for setting a drive signal for each nozzle, and the nozzles of the second nozzle group are a control device for setting a common drive signal. Connected with the
An inkjet apparatus characterized by the above.   The inkjet apparatus according to claim 1, wherein the number of nozzles of the first nozzle group is smaller than the number of nozzles of the second nozzle group.   The inkjet apparatus according to claim 1, wherein the number of nozzles in the first nozzle group is only one nozzle.   The nozzles of the first nozzle group further include a complementary nozzle for complementing when ink is not ejected, and the complementary nozzle is disposed adjacent to an ink landing position. Item 4. The inkjet device according to any one of Items 1 to 3.   The inkjet apparatus according to claim 4, wherein the complementary nozzle is disposed at a position where the complementary nozzle is applied on one side or both sides with respect to the ink landing position.   The inkjet apparatus according to claim 5, wherein the complementary nozzle is a nozzle that lands at a position far from a center of the pixel.

Images