JP4921690B2 - Inkjet coating apparatus and organic EL display device manufacturing method - Google Patents

Description

The present invention is used in forming the luminescent layer of organic EL, 1 single pixel is R (red), it is composed of G (green), a plurality of dots corresponding to the three colors of B (blue) The present invention relates to a method for manufacturing an organic EL display device and an ink jet coating device that coats a predetermined dot with an ink droplet amount corresponding to a command electric quantity on a display substrate.

  In recent years, with the development of PCs and mobile phones, the demand for display devices has increased. Organic EL display devices are attracting attention as promising candidates for next-generation display devices that replace the currently mainstream liquid crystal display devices. The reason is that the organic EL display device has many advantages as described below, as compared with the liquid crystal.

  1) Since the organic EL display device uses a self-luminous element, it does not require a backlight, and there is no need to inject liquid crystal between two glasses. It is possible to reduce the weight.

  2) Excellent characteristics relating to the viewing angle and response speed, which are the issues of concern for liquid crystal display devices.

  Luminescent materials for organic EL display devices are roughly classified into low-molecular types and high-molecular types, and the light-emitting layer forming techniques are different from each other. In the low molecular type, the light emitting layer is formed by a mask vapor deposition technique, and a thin metal mask of several tens of microns must be used, and it is difficult to make a large mask with high accuracy, so it is not suitable for enlargement.

  On the other hand, in the polymer type, the light emitting polymer is dissolved in an organic solvent, and this is applied to predetermined dots on the substrate with an inkjet head. Since a mechanism capable of greatly changing the relative position between the ink jet head and the substrate can be easily realized, the method of applying the polymer material with the ink jet head is suitable for an increase in size.

  Also, in terms of productivity, the low molecular weight type uses a lot of materials because it uses vapor deposition. On the other hand, since the ink jet system applies only a necessary amount to a predetermined place, the material utilization efficiency is very high.

  As described above, since the ink jet method is superior in size and productivity, there are many cases of manufacturing an organic EL display device.

  Conventionally, as an ink jet coating apparatus used for coating a light emitting material to form a light emitting layer of an organic EL display device, a plurality of pixels are spaced apart from each other in a predetermined direction on a substrate constituting the display. An ink jet head for ejecting and applying an ink droplet amount to each pixel, and an ink droplet ejected from each nozzle, for forming a plurality of existing row-arranged pixel groups (lines) in a column direction Adjust the command voltage applied to each actuator in order to make the average value of the amount of ink droplets in each line ejected and applied from each nozzle to the substrate equal to a predetermined value. A command voltage regulator is provided.

  This is achieved by matching the pitch between the plurality of nozzles of the inkjet head with the pitch between pixels of the substrate so that the average value of the droplet amount of each nozzle in the same head becomes a predetermined value. Then, the light emitting material is sequentially applied to predetermined dots by the inkjet head from the dots of the pixels arranged on the edge of the substrate. Here, one pixel of the substrate is composed of a plurality of dots corresponding to three colors of R, G, and B.

  A display device made of organic EL is required to have a characteristic of displaying brightness uniformly over the entire display area. In order to realize this, conventionally, the variation in droplet amount between nozzles has been made as small as possible by the following procedure.

  (1) The command voltage to the actuator corresponding to the target droplet amount of the luminescent material is set by the command voltage generator.

  (2) The luminescent material is actually ejected from each nozzle of each inkjet head, the amount of droplets in the corresponding row arrangement pixel group from each nozzle is measured, and the droplet amount in the corresponding row arrangement pixel group Find the average value of.

  (3) The average value of the droplet amounts in the remaining row arrangement pixel groups is aligned with a predetermined value of the average value of the droplet amounts in the corresponding row arrangement pixel group obtained in (2).

  As described above, even if fine tuning is performed to reduce the variation in the amount of liquid droplets between nozzles, the manufactured organic EL display device appears to have striped luminance unevenness (hereinafter referred to as stripe unevenness). There is. This is because even if fine tuning is performed as described above, variations in the average value of the droplet amount due to variation in characteristics between actuators, variation in nozzle shape, and the like are observed.

  Therefore, conventionally, when the droplet amount is calculated from the droplet shape of the ink that is the light emitting material being discharged in the same inkjet head, or the droplet diameter after discharge application (after landing), if the difference is large, The command voltage was finely adjusted by the command voltage regulator, and the average droplet volume between nozzles was adjusted. In this way, fine tuning to drive the droplet amount variation between the nozzles to the target value has to be performed a plurality of times, and adjusting the droplet amount takes a lot of time and effort. This is expected to further increase the burden on this work if the number of nozzles in the inkjet head is further increased.

  Further, when the variation in the average droplet amount of the light emitting material between adjacent row arrangement pixel groups is larger than the variation in the droplet amount in one row arrangement pixel group applied by the same nozzle, the human is The luminance variation of the line is felt as two straight lines with different brightness, and it becomes easy to recognize the unevenness of the line.

  Furthermore, as another problem, the fine tuning requires a considerable amount of time and effort, for example, several hours for the coating time, for example, several minutes, which causes productivity deterioration and cost increase.

  The present invention has been made to solve such a problem, and even if there is a difference between adjacent row-arranged pixel groups and the average amount of liquid droplets, an ink jet that is difficult for a viewer to see a display device is recognized as streak irregularity. Providing a coating device, and making fine tuning to align the amount of droplets to be applied to a substrate is rougher than before, and manufacturing high-quality organic EL display devices that can shorten the adjustment time for fine tuning It aims to provide a method.

In order to achieve the above object, an invention corresponding to claim 1 is used for applying a light emitting material to form a light emitting layer of an organic EL display device, and within a predetermined region on a substrate constituting the display device. In order to form a plurality of lines in a row direction in which a plurality of pixels are spaced apart from each other in the row direction in the column direction, each pixel is made of the same kind of light emitting material as the light emitting material. An inkjet head in which a plurality of nozzles for ejecting and applying ink droplet amounts are arranged in a row direction, a plurality of actuators for controlling the amount of ink droplets ejected from each nozzle according to a command voltage, A command voltage regulator is provided for adjusting the command voltage applied to each actuator in order to make the average value of the ink droplet amount in each line discharged and applied from the nozzle to the substrate equal to a predetermined value. And the ink jet coating apparatus, adds the command voltage regulator of the noise voltage you added variation amount within a predetermined range in drop volume ejected from the nozzles against the command voltage to each of said nozzles comprising a noise generating means, and a superimposition means for superimposing said command voltage to noise voltage from said noise generating means, the noise voltage Vn from said noise generating means, (in-line liquid droplet amount between 2 lines and wherein the difference between the average value) / (2 lines drop volume average), and the noise voltage Vn, determining based on the numerical value Vn / Vc of the command voltage Vc is obtained by a that matches An inkjet coating apparatus.

In order to achieve the above object, an invention corresponding to claim 2 is used for applying a light emitting material to form a light emitting layer of an organic EL display device, and within a predetermined region on a substrate constituting the display device. In order to form a plurality of lines in a row direction in which a plurality of pixels are spaced apart from each other in the row direction in the column direction, each pixel is made of the same kind of light emitting material as the light emitting material. An inkjet head having a plurality of nozzles for discharging and applying ink droplet amounts arranged in the column direction, and a plurality of actuators for controlling the amount of ink droplets discharged from the nozzles according to a command voltage, respectively. A command given to each actuator in order to make the average value of the ink droplet amount in each line ejected and applied from the respective nozzles to the substrate to a predetermined value. A command voltage regulator that adjusts the pressure, and a noise voltage that adds a variation amount within a predetermined range to the droplet amount discharged from each nozzle with respect to the command voltage of the command voltage regulator for each nozzle a noise generating means for adding, by an ink jet application apparatus noise voltage anda superimposing means for superimposing on said command voltage from said noise generating means, comprising a plurality of pixels formed in a row direction before SL on the substrate A noise value is given to each actuator by the noise generating means and the superimposing means within a predetermined range for each of the row-arranged pixel groups, whereby an ink droplet amount from each nozzle is obtained. the so as to fluctuated, the noise voltage Vn from said noise generating means, and (a difference in line droplet volume average between 2 lines) / (droplet volume mean of two lines), the noise A voltage Vn, a method of manufacturing an organic EL display device and determines, based on the number values obtained by the Vn / Vc matches the command voltage Vc.

  According to the present invention, even if there is a difference between adjacent row-arranged pixel groups and the average amount of liquid droplets, it is possible to obtain an ink jet coating apparatus in which a person watching a display device is not easily recognized as streak irregularity.

  In addition, according to the present invention, fine tuning for aligning the amount of droplets to be applied to the substrate becomes rougher than before, adjustment time for fine tuning can be shortened, and the price can be reduced accordingly. A method for manufacturing a high-quality organic EL display device can be obtained.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an inkjet coating apparatus and an organic EL display device manufacturing method according to the present invention will be described with reference to the drawings.

  An embodiment of an inkjet coating apparatus of the present invention is generally an inkjet coating apparatus that applies droplets containing a light emitting material on a substrate by discharging droplets containing the light emitting material in a predetermined arrangement state, and a plurality of the same type of light emitting material is applied to the substrate. The amount of liquid droplets discharged from each nozzle is varied within a predetermined range with respect to a setting value that determines the amount of the same type of liquid droplets discharged from the nozzles and the same type of liquid droplets discharged from the plurality of nozzles as a predetermined amount. It is an inkjet coating apparatus provided with the noise generation means which adds the noise to add to each of the said nozzle.

  Specifically, as shown in FIGS. 1 to 3, for example, a plurality of regions in a predetermined region on the substrate 3 constituting the organic EL display device and spaced from each other in the row direction (line) and the column direction. An ink jet coating apparatus having an ink jet head 8 at a position where a pixel S is to be formed, and a plurality of pixels S by ejecting and applying ink droplet amounts of light emitting materials of R, G, and B colors in a desired arrangement. 3 is a unit that varies the ink droplet amount within a predetermined range for each row-arranged pixel group formed of a plurality of pixels formed in the row direction on the substrate 3 (for example, the noise generating unit 19 and FIG. 3). (Comprising superimposing means 23).

  FIG. 1 is an external view showing a schematic configuration of an ink jet coating apparatus, and FIG. 2 is a perspective view of an ink jet mechanism which is a main part of the ink jet coating apparatus. In the figure, reference numeral 1 denotes a base, and a movable stage 2 is provided on the X and Y planes of the upper surface of the base 1. On the stage 2, a substrate 3 is supported and fixed in a replaceable manner by fixing means (not shown).

  As shown in FIG. 12, the head mechanism 5 includes a liquid chamber 61, a nozzle body 62 having a plurality of (here, five, a, b, c, d, and e as shown in FIG. 8) nozzles 12, a diaphragm. 63, a piezo element 64, a power source 65 constituting the command voltage generator 21, an adjustment resistor 66 constituting the command voltage regulator 22, and a communication passage 67 communicating the liquid chamber 61 and the nozzle 12 included in the nozzle body 62. Yes.

  In the liquid chamber 61, ink made of a luminescent material is stored, and the ink in the liquid chamber 61 is ejected to the dots of the pixels S formed on the substrate 3 through the plurality of nozzles 12 included in the nozzle body 62. It is configured to be able to. That is, when a voltage from the power source 65 is applied to the liquid chamber 61 side of the communication path 67, a piezoelectric element 64, which is an example of the actuator 26 described later, is deformed accordingly, thereby pulling the diaphragm 63 and moving the inside of the communication path 67. It is comprised so that it may become a negative pressure. As a result, the ink in the liquid chamber 61 is ejected to the dots of the pixels of the substrate 3 through the nozzles 12 included in the nozzle body 62.

  Further, a gantry 4 is laid over the stage 2 on the base 1, and a head mechanism 5 is attached to the gantry 4. The head mechanism 5 is composed of four ink jet head mechanisms 6, one of which includes a solvent ink jet head 7 constituting solvent application means for discharging the solvent at the lower end of the head mechanism 5. The remaining three include ink inkjet heads 8 that constitute ink application means for ejecting three colors of ink (R, G, B) at the lower end thereof.

  The four inkjet head mechanisms 6 each include a mechanism 9 that rotates the inkjet heads 7 and 8 by θ, a mechanism 10 that can be finely adjusted in the Y direction, and a mechanism 11 that can be finely adjusted in the Z direction. Each of the inkjet heads 7 and 8 includes a plurality of nozzles arranged in series as will be described later.

  Here, the head mechanism 5 is fixed, and the relative positions of the solvent inkjet head 7, the ink inkjet head 8, and the substrate 3 are changed by controlling the movement of the XY stage 2.

  On the substrate 3, a plurality of pixels are formed on a plurality of lines arranged side by side in a state of being distributed in a lattice pattern, and each pixel has R (red), G (green), B ( It is composed of a plurality of dots corresponding to the three colors (blue).

  Here, a line is for arranging a plurality of pixels in a predetermined area on the substrate 3 for each virtual straight line arranged in parallel in the row direction (lateral direction) in which the pixels are to be formed. It is.

  As shown in FIG. 3, the embodiment of the control device for the ink jet coating apparatus of the present invention is within a predetermined region on the substrate 3 of the organic EL display device, and a plurality of virtual lines such as a to e in the row direction. In order to form a plurality of pixels S in each of the lines a to e, an ink droplet amount is ejected and applied, and is configured as follows.

That is, the ink jet head 8 having a plurality of nozzles 12 for ejecting each applied ink droplet volume for each line a to e, respectively command electric quantity of ink droplet volume ejected from the nozzles 12 a plurality of the actuators 26, for example, the command voltage generator 21, for example, command voltage generating means 20 consists of command voltage regulator 22, and, for example, noise generator 24, for example, noise generating means comprising noise adjuster 25 is controlled in accordance 19 and superimposing means 23.

  Among them, the noise generating means 19 and the superimposing means 23 are means for varying the ink droplet amount within a predetermined range of the present invention, that is, a row composed of a plurality of pixels S formed in the row direction on the substrate 3. The ink droplet amount varies within a predetermined range for each arrangement pixel group (for each line), that is, the applied noise component is different for each nozzle.

  In this case, the command electric quantity adjusting means 20 provides the command electric quantity to be given to each actuator 26 in order to make the average value of the ink droplet quantity in each line a to e discharged and applied to the substrate 3 from each nozzle 12 equal to a predetermined value. Adjust the amount. Also, each noise generating means 19 is given to each actuator 26 and generates different noise values for adjacent pixels with respect to the command electricity quantity for each of the lines a to e. Further, the superimposing unit 23 superimposes the command electric quantity from the command electric quantity adjusting unit 20 and the noise value from the noise generating unit 19 for each line. As a result, the actuator 26 discharges the ink droplet amount corresponding to the output of each superimposing means 23, and the ink droplet amount from the nozzles 12 in each line a to e varies within a predetermined variation amount range. You can make it.

  Next, the embodiment described above will be described in detail. For example, as shown in FIG. 4, the noise generator 24 uses a digital random number generator 241 and a DA converter 242.

  Then, a voltage based on a random number having a normal distribution with a standard deviation of 1 as shown in FIG. 5 is supplied from the noise generator 24 in FIG. 3, amplified by α times by the noise adjuster 25 in FIG. The command voltage is superposed by means 23. That is, as shown in FIG. 6, when the command voltage is Vc and the noise voltage output from the noise generator 24 is Vn, the command waveform Wc to the actuator 26 is Vc + Vn, which is Vn / Vc × 100 (%). The voltage to which the noise component is added is supplied to the actuator 26.

  Assuming that the command voltage V and the droplet amount Q have the relationship as shown in FIG. 7, when the command voltage changes from Vc to Vc + Vn, a noise component corresponding to Qn is added to the droplet amount.

  If Vn = 4 × α, a variation of ± 4α / Vc × 100 (%) is added to the command voltage with the establishment of 99.99%. For example, when it is desired to add 5% variation to Vc = 100 V, the amplification factor of the noise adjuster 25 may be set to α = 1.25.

  Further, when the actuator 26 is a piezoelectric element of the piezo element 64 as shown in FIG. 12, when the command waveform Wc in FIG. 6 is applied, the applied voltage is delayed as shown in the drive waveform Wd due to the influence of a mechanical load. Waveform with vibration.

  Next, the point that the non-uniformity of the stripe, which is a conventional problem, is improved will be described with reference to FIGS. An ink jet head 6 (hereinafter referred to as a head) in FIG. 8 is fixed on the XY plane and includes a plurality of nozzles a, b, c, d, e. When the substrate 3 mounted on the XY stage 2 of FIG. 1 that can move in the X and Y directions moves in the direction of the head 6, ink is sequentially discharged from each nozzle 12 to each pixel S in the corresponding line. .

  As described above, the addition of the noise component is performed at the discharge interval, and the magnitude of the noise component varies with normality within one line. FIG. 9A shows the distribution of the droplet amount of the line La applied by the nozzle a and the distribution of the droplet amount of the line Lb applied by the nozzle b. Here, the difference between the droplet volume average values is ΔD, and the standard deviation of both is the same. FIG. 9B shows the droplet amount distribution of the line La and the line Lb after adding the noise component Vn. When FIG. 9B is compared with FIG. 9A, the average value of the nozzle a and the nozzle b is not changed, but the standard deviation is increased by adding the noise component.

  This makes it difficult for a human to recognize a plurality of continuous pixels applied with the same nozzle as a line and to recognize a difference in luminance between lines.

The method for determining the noise voltage Vn is based on a numerical value obtained on the assumption that (difference in average amount of droplets in two lines) / (average droplet amount in two lines) and Vn / Vc match. However, in practice, a sensitivity test by a plurality of humans may be performed, and a value at which streak unevenness is not noticeable to the extent that the noise component is too large to produce a rough feeling may be determined.

  10 and 11 are block diagrams showing a specific configuration of the ink jet coating apparatus of the present invention. FIG. 10 shows a configuration in which the noise generating means 19 described above is arranged for each of the plurality of actuators 26. Specifically, the noise generating means 19a, 19b, 19c, 19d... Generates noise independently for each of the plurality of command voltage regulators 22a, 22b, 22c, 22d... And the actuators 26a, 26b, 26c, 26d. And superimposing means 23a, 23b, 23c, 23d ... between the command voltage regulators 22a, 22b, 22c, 22d ... and the actuators 26a, 26b, 26c, 26d ... Each of the noise generating means 19a to 19d... Is applied with 2% noise so as to cause variation independently of each other. In addition, the command voltage from one command voltage generator 21 is input to the command voltage regulators 22a, 22b, 22c, 22d.

FIG. 11 is configured such that noises having different random numbers obtained from one noise generating means 19 are given to a plurality of actuators 26 via a switch 27 having a plurality of contacts and a plurality of superimposing means. Specifically, command voltage regulators 22a, 22b, 22c, 22d... Are arranged between the actuators 26a, 26b, 26c, 26d.
.. Are connected to one end of contacts 27a, 27b, 27c, 27d,... Of the switch 27, and the other end of the contacts 27a, 27b, 27c, 27d,. Is provided with noise of different random numbers obtained from one noise generating means 19. In addition, the command voltage from one command voltage generator 21 is input to the command voltage regulators 22a, 22b, 22c, 22d. In such a configuration, a switching signal from a main control unit (not shown) is sequentially given to the contacts 27a, 27b, 27c, 27d,... Of the switch 27, whereby each contact 27a, 27b, 27c, 27d,. The noises are sequentially closed, and noises with different random numbers are sequentially applied from the noise generating means 19. Only the switch 27 in the switch 27 corresponding to the actuator 26 to be discharged is turned on, and the noise component is selectively superimposed by the superimposing means 23.

  According to the embodiment described above, when forming a plurality of pixels in a plurality of virtual lines in a predetermined region on the substrate in the row direction, the ink jet heads 8 for ink in one line By varying the amount of ejected ink droplets within a range of predetermined variation amounts, even if there is a difference in the average value of the amount of ejected droplets between adjacent ink jet heads 8, It becomes difficult for humans to recognize as muscle irregularities.

  The present invention can be applied in various ways as long as the effects of the present invention are not impaired. For example, as the noise generating means 19, since the avalanche current of the Zener diode has a characteristic close to white noise, a method of amplifying this to generate a random noise component may be used.

  In the above-described embodiment, the case where the voltage drive type piezo element is used as the actuator 26 has been described. However, the actuator 26 can be similarly implemented even if it is a current drive type actuator that expands ink with a heater or the like and discharges the ink. .

  Furthermore, the present invention can be applied to any of the vertical stove arrangement, the delta arrangement, and the square arrangement as a technique for arranging the R (red), G (green), and B (blue) in each pixel described above. Needless to say.

1 is an external view of an inkjet coating apparatus according to an embodiment of the present invention. The perspective view of the inkjet mechanism which concerns on the same embodiment. The block diagram for demonstrating the structure of the control apparatus in embodiment of FIG. The block diagram for demonstrating the noise generator of FIG. The figure for demonstrating the noise generator of FIG. The figure for demonstrating the operation | movement of FIG. The figure for demonstrating the command voltage generator of FIG. The figure for demonstrating operation | movement of embodiment of this invention. The figure for demonstrating the effect of FIG. The figure for demonstrating the specific embodiment of FIG. The figure for demonstrating the specific embodiment of FIG. The figure for demonstrating the conventional inkjet head mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... XY stage, 3 ... Board | substrate, 4 ... Stand, 5 ... Head mechanism part, 6 ... Inkjet head, 7 ... Inkjet head for solvent, 8 ... Inkjet head for ink, 9 ... Mechanism to rotate (theta), DESCRIPTION OF SYMBOLS 10 ... Mechanism enabling fine adjustment in Y direction, 11 ... Mechanism enabling fine adjustment in Z direction, 12 ... Nozzle, 19 ... Noise generating means 19a-19d ... Noise generating means, 20 ... Command voltage generating means, 21 ... Command voltage generator, 22 ... Command voltage regulator, 22a-22d ... Command voltage regulator, 23 ... Superimposing means, 23a-23d ... Superimposing means, 24 ... Noise generator, 25 ... Noise regulator, 26 ... Actuator, 26a 26d ... Actuator, 27 ... Switch, 27a-27d ... Contact, 61 ... Liquid chamber, 62 ... Nozzle body, 63 ... Diaphragm, 64 ... Piezo element, 65 ... Electricity , 66 ... adjustment resistor, 67 ... communicating passage, 241 ... digital random number generator, 242 ... DA converter.

Claims (2)

A row arrangement in which a plurality of pixels are spaced apart from each other in a predetermined direction in a predetermined region on a substrate constituting the display device, which is used for applying a light emitting material to form a light emitting layer of an organic EL display device. A plurality of nozzles for ejecting and applying an ink droplet amount made of the same kind of light emitting material as the light emitting material to each of the pixels is formed in the column direction. an inkjet head arranged, ink droplets in each line the plurality of actuators controlled in accordance with the respective command voltage amount of ink droplets ejected from each nozzle to be discharged applied from said each nozzle to the substrate In order to align the average value of the amount to a predetermined value, in an inkjet coating apparatus including a command voltage adjuster that adjusts a command voltage applied to each actuator,
A noise generating means for adding the command voltage regulator of the noise voltage you added variation amount within a predetermined range in drop volume ejected from the nozzles against the command voltage to each of said nozzle,
Anda superimposing means for superimposing a noise voltage from said noise generating means to said command voltage,
The noise voltage Vn from the noise generating means is ( difference in average droplet amount between two lines) / (average droplet amount in two lines), the noise voltage Vn, and Vn of the command voltage Vc. / Vc inkjet coating apparatus and determines on the basis of the numerical values obtained by the that match. A row arrangement in which a plurality of pixels are spaced apart from each other in a predetermined direction in a predetermined region on a substrate constituting the display device, which is used for applying a light emitting material to form a light emitting layer of an organic EL display device. A plurality of nozzles for ejecting and applying an ink droplet amount made of the same kind of light emitting material as the light emitting material to each of the pixels is formed in the column direction. an inkjet head arranged, an inkjet head mechanism having a plurality of actuators for controlling in response to each command voltage amount of ink droplets ejected from each nozzle,
A command voltage adjuster for adjusting a command voltage applied to each actuator in order to align an average value of the ink droplet amount in each line applied to the substrate from each nozzle to a predetermined value;
Noise generating means for adding, for each nozzle, a noise voltage that adds a variation amount within a predetermined range to the amount of droplets ejected from each nozzle with respect to the command voltage of the command voltage regulator;
Superimposing means for superimposing a noise voltage from the noise generating means on the command voltage;
The inkjet application apparatus having a
The pre-Symbol the amount of ink droplets each of a plurality of rows arranged group of pixels consisting of pixels formed in a row direction on the substrate within a predetermined range, said noise generating means and the noise value each actuator by said superimposing means - So that the amount of ink droplets from each nozzle can be dispersed,
The noise voltage Vn from the noise generating means is ( difference of average droplet amount in two lines) / (average droplet amount in two lines), the noise voltage Vn, and Vn of the command voltage Vc. a method of manufacturing an organic EL display device characterized by / Vc is determined based on the number value obtained by the matching.

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