JP2007111679A - Coater and its adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adjusting method for a coater which can adjust the dispersion of the amount of discharged droplets between nozzles, and the dispersion of positions where the discharged droplets land on pixels, and a coater equipped with such an adjusting mechanism. <P>SOLUTION: The coater comprises a head 132 equipped with a plurality of nozzles 135 for applying droplets for forming a photoactive layer held by a pair of electrodes, a discharge mechanism 136 for discharging droplets from the nozzles, and an adjusting mechanism 140 having a substrate SUB for adjustment with a plurality of pixel arrays each in which a plurality of pixels having a plurality of different pixel areas are arranged in one direction at an equal pitch, applying droplets toward the pixels of the pixel arrays from nozzles, and controlling the discharge mechanism based on the spreading state of the droplets applied to each pixel of the substrate for adjustment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coating apparatus and a method for adjusting the coating apparatus, and in particular, selection of an ink jet system that applies a droplet for forming a photoactive layer held between a pair of electrodes constituting a self-luminous element. The present invention relates to a coating apparatus adopting a coating method and a method for adjusting the coating apparatus.

  In recent years, organic electroluminescence (EL) display devices have attracted attention as flat display devices. Since this organic EL display device is a self-luminous element, it has a wide viewing angle, can be thinned without requiring a backlight, has low power consumption, and has a high response speed. ing.

  Because of these characteristics, organic EL display devices are attracting attention as potential candidates for next-generation flat display devices that can replace liquid crystal display devices. Such an organic EL display device includes an array substrate configured by arranging organic EL elements in a matrix form with a photoactive layer containing an organic compound having a light emitting function between an anode and a cathode. . The photoactive layer is formed by a selective coating method such as an ink jet method using a polymer material, for example.

When such a selective coating method is adopted, display quality degradation such as display unevenness occurs due to variations in droplet application accuracy between nozzles that discharge droplets for forming a photoactive layer. There is a fear. For this reason, it is required to be able to adjust the variation in droplet discharge amount between nozzles and the landing position of droplets. For example, a method has been proposed in which the droplet flying state until landing on the substrate is photographed with a high-speed camera, the droplet amount is calculated based on the velocity and density in the droplet flying state, and the discharge amount is adjusted. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2003-028696

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce variations in the discharge amount of droplets between nozzles and variations in landing positions of discharged droplets on pixels by a simple method. It is an object of the present invention to provide a method of adjusting a coating apparatus that can be adjusted and a coating apparatus including such an adjustment mechanism.

The adjustment method of the coating apparatus according to the first aspect of the present invention is as follows.
In a coating apparatus including a plurality of nozzles for coating droplets for forming a photoactive layer held between a pair of electrodes,
Preparing an adjustment substrate having a plurality of pixel columns in which a plurality of pixels having different pixel sizes at a plurality of levels are arranged in one direction at an equal pitch;
A step of applying droplets from the nozzles of the coating apparatus toward the pixels of each pixel row of the adjustment substrate;
An adjustment step of adjusting the discharge amount of the droplets discharged from each nozzle based on the spread state of the droplets applied to each pixel of the adjustment substrate;
It is provided with.

The adjustment method of the coating apparatus according to the second aspect of the present invention is as follows.
In a coating apparatus including a plurality of nozzles for coating droplets for forming a photoactive layer held between a pair of electrodes,
Preparing an adjustment substrate including a plurality of pixel columns in which a plurality of pixels of equal sizes having different pixel pitches at different levels are arranged in one direction;
A step of applying droplets from the nozzles of the coating apparatus toward the pixels of each pixel row of the adjustment substrate;
An adjustment step of adjusting the landing position of each droplet discharged from each nozzle on each pixel based on the spread state of the droplet applied to each pixel of the adjustment substrate;
It is provided with.

The coating apparatus according to the third aspect of the present invention is:
A plurality of nozzles for applying droplets for forming a photoactive layer held between a pair of electrodes;
A discharge mechanism for discharging droplets from each nozzle;
A liquid crystal substrate is provided with an adjustment substrate having a plurality of pixel columns in which a plurality of pixels having different pixel areas at different levels and arranged in one direction at equal pitches, and droplets are respectively directed from the nozzles toward the pixels of the pixel columns of the adjustment substrate. An adjustment mechanism that adjusts the discharge amount of liquid droplets discharged from each nozzle by controlling the discharge mechanism based on the spread state of the liquid droplets applied to each pixel of the adjustment substrate,
It is provided with.

A coating apparatus according to a fourth aspect of the present invention is:
A plurality of nozzles for applying droplets for forming a photoactive layer held between a pair of electrodes;
A discharge mechanism for discharging droplets from each nozzle;
A liquid crystal substrate is provided with an adjustment substrate having a plurality of pixel rows in which a plurality of pixels of equal sizes having different pixel pitches at different levels are arranged in one direction, and each droplet is directed from each nozzle toward a pixel in each pixel row of the adjustment substrate. An adjustment mechanism that controls the ejection mechanism based on the spread state of the droplets applied to each pixel of the adjustment substrate to adjust the landing position of each droplet discharged from each nozzle on each pixel. ,
It is provided with.

  According to the present invention, there is provided a coating apparatus adjustment method capable of adjusting variations in the discharge amount of droplets between nozzles and variations in landing positions of discharged droplets on pixels by a simple method, and such a method. A coating apparatus provided with an adjusting mechanism can be provided. This makes it possible to provide a display device with good display quality.

  A display device according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a self-luminous display device such as an organic EL (electroluminescence) display device will be described as an example of the display device.

  As shown in FIG. 1, the organic EL display device 1 includes an array substrate 100 having a display area 102 for displaying an image. The display area 102 includes a plurality of pixels PX (R, G, B) arranged in a matrix.

  In addition, the array substrate 100 includes a plurality of scanning lines Ym (m = 1, 2,...) Arranged along the row direction of the pixels PX (that is, the Y direction in FIG. 1) and columns substantially orthogonal to the scanning lines Ym. A plurality of signal lines Xn (n = 1, 2,...) Arranged along the direction (that is, the X direction in FIG. 1) and power supply for supplying power to the first electrode 60 side of the organic EL element 40 Line P.

  Furthermore, the array substrate 100 has a scanning line driving circuit 107 that supplies a scanning signal to each of the scanning lines Ym and a signal that supplies a video signal to each of the signal lines Xn in the peripheral area 104 along the outer periphery of the display area 102. A line driving circuit 108. All the scanning lines Ym are connected to the scanning line driving circuit 107. All signal lines Xn are connected to the signal line driving circuit 108.

  Each pixel PX (R, G, B) includes a pixel circuit and a display element that is driven and controlled by the pixel circuit. The pixel circuit electrically separates an on pixel and an off pixel and has a function of holding a video signal to the on pixel, and a display element based on a video signal supplied via the pixel switch 10. The driving transistor 20 supplies a desired driving current, and the storage capacitor element 30 holds the gate-source potential of the driving transistor 20 for a predetermined period. The pixel switch 10 and the driving transistor 20 are constituted by, for example, thin film transistors, and here, polysilicon is used for a semiconductor layer.

  The display element is composed of organic EL elements 40 (R, G, B) which are self-luminous elements. That is, the red pixel PXR includes an organic EL element 40R that mainly emits light corresponding to the red wavelength. The green pixel PXG includes an organic EL element 40G that mainly emits light corresponding to the green wavelength. The blue pixel PXB includes an organic EL element 40B that mainly emits light corresponding to the blue wavelength.

  The various organic EL elements 40 (R, G, B) have basically the same configuration. For example, as shown in FIG. 2, the first electrode 60 formed in an independent island shape for each pixel PX, and the first The second electrode 66 is disposed opposite to the electrode 60 and formed in common for all the pixels PX, and the photoactive layer 64 held between the first electrode 60 and the second electrode 66. Yes.

  Here, the pixel switch 10 is disposed in the vicinity of the intersection between the scanning line Ym and the signal line Xn. The pixel switch 10 has a gate electrode connected to the scanning line Ym, a source electrode connected to the signal line Xn, and a drain electrode connected to one electrode constituting the storage capacitor 30 and the gate electrode of the drive transistor 20. The source electrode of the drive transistor 20 is connected to the other electrode constituting the storage capacitor element 30 and the power supply line P, and the drain electrode is connected to the first electrode 60 of the organic EL element 40. The power supply line P is connected to a first electrode power line (not shown) arranged around the display area 102. The second electrode 66 of the organic EL element 40 is disposed around the display area 102 and is connected to a second electrode power supply line (not shown) that supplies a common potential, here, a ground potential.

  As shown in FIG. 2, the array substrate 100 includes a plurality of organic EL elements 40 disposed on the wiring substrate 120. Note that the wiring substrate 120 is formed on an insulating support substrate such as a glass substrate or a plastic sheet, the pixel switch 10, the driving transistor 20, the storage capacitor element 30, the scanning line driving circuit 107, the signal line driving circuit 108, and various wirings (scanning). Line, signal line, power supply line, etc.).

  The first electrode 60 constituting the organic EL element 40 is disposed on an insulating film (for example, a planarizing layer) on the surface of the wiring substrate 120 and functions as an anode.

  The photoactive layer 64 includes at least a light emitting layer. The photoactive layer 64 may be configured as a layer other than the light-emitting layer, for example, a two-layer structure including a hole transport layer formed in common for each color and laminated with a light-emitting layer formed in each color pixel. , A hole injection layer, a blocking layer, an electron transport layer, an electron injection layer, a buffer layer, and the like, or a layer in which these are functionally combined may be included. In the photoactive layer 62, the light emitting layer may be an organic material, and the layers other than the light emitting layer may be an inorganic material or an organic material. The light-emitting layer is formed of an organic compound having a light-emitting function that emits red, green, or blue light. That is, the organic EL element 40R of the red pixel PXR includes a photoactive layer 64R that mainly emits red light. The organic EL element 40G of the green pixel PXG includes a photoactive layer 64G that mainly emits green light. The organic EL element 40B of the blue pixel PXB includes a photoactive layer 64B that mainly emits blue light.

  The second electrode 66 is disposed in common with each organic EL element 40 on the photoactive layer 64 (R, G, B). The second electrode 66 is formed of a metal material having an electron injection function and functions as a cathode.

  Next, a coating apparatus for applying droplets for forming the photoactive layer 64 will be described. Here, a coating apparatus that selectively applies droplets by an inkjet method will be described. For example, as illustrated in FIG. 3, the coating apparatus 130 includes a stage 131 on which a substrate as a workpiece W (that is, the wiring substrate 120 on which the first electrode 60 has been formed) is placed. A head 132 is disposed above the stage 131. Below the stage 131, a rail 133 extending in the X direction and a rail 134 extending in the Y direction are arranged so as to be substantially orthogonal to each other. The stage 131 can be moved along the X direction on the rail 133 by a driving mechanism (not shown). The rail 133 is movable along the Y direction on the rail 134 together with the stage 131 by a driving mechanism (not shown). With such a configuration, the workpiece W placed on the stage 131 can be moved relative to the head 132 in both the X direction and the Y direction substantially orthogonal to each other.

  As shown in FIG. 4, the head 132 has a plurality of, for example, 256 nozzles 135 for applying droplets for forming the photoactive layer 64. In the example shown in FIG. 4, these nozzles 135 are arranged in a line, but may be arranged in a plurality of lines. The head 132 having such a configuration discharges droplets from each nozzle 135 based on the control by the discharge mechanism 136. The discharge mechanism 136 includes, for example, a piezoelectric element disposed corresponding to each nozzle 135, and controls the application accuracy of the droplet by controlling the voltage applied to the piezoelectric element. . For example, it is possible to control the discharge amount of the droplet based on the voltage level, the pulse width of the pulse voltage, and the like, and the droplet discharge timing is determined by the voltage application timing (that is, the landing position where the droplet reaches each pixel). It is possible to control the discharge timing.

  Next, a method for adjusting the coating accuracy of droplets ejected from each nozzle in the above-described coating apparatus will be described.

  As shown in FIG. 5, the adjustment method described here is performed using a dedicated adjustment substrate SUB. The adjustment substrate SUB is formed, for example, in the same manner as the wiring substrate 120 on which the normal first electrode 60 is formed, and includes pixels PX arranged in a matrix. However, the pixels PX on the adjustment substrate SUB are formed under conditions different from normal ones (refer to each adjustment method described later for details). The head 132 includes a plurality of nozzles 135 arranged in a line and is movable in the X direction with respect to the adjustment substrate SUB.

<First adjustment method>
In the first adjustment method, the variation in the discharge amount of droplets between nozzles is adjusted. First, as shown in FIG. 6, an adjustment substrate SUB having a plurality of pixel columns A in which a plurality of pixels PX having different pixel sizes at a plurality of levels are arranged at one pitch in one direction, that is, the X direction is prepared. In the example shown here, each pixel PX has a quadrangular shape, and the pixel size corresponds to the opening area of each pixel PX. For each pixel column A, when the pixel size of the pixel PX arranged on the leftmost side in the drawing is a, the pixel PX arranged on the right side has a pixel size (1 + k) × a, (1 + 2k) with a modulation factor k. × a, (1 + 3k) × a. For example, the modulation factor k of each pixel PX is increased or decreased in the range of 0.1 to 5%. This increase / decrease range is changed according to the required adjustment accuracy.

  Further, the center (center of gravity position) C of each pixel PX is as indicated by the intersection of the broken lines, and each pixel PX is arranged at an equal pitch P1 along the X direction. This pixel pitch P1 is equal to the coating pitch P2. The reason why the barycentric positions of the pixels PX are arranged in a grid is that the influence on the spread due to the landing position of the droplets is taken into consideration. In the example shown in FIG. 6, the shape of the pixel PX is shown as a square. However, the shape of the pixel is not particularly limited to this example. It is desirable to ensure.

  Droplets are applied from the nozzles 135 of the coating apparatus toward the pixels PX of the pixel rows A of the adjustment substrate SUB. That is, the nth nozzle row 135n is made to correspond to the nth pixel row An on the adjustment substrate SUB, and the (n + 1) th nozzle 135 (n + 1) is made to correspond to the (n + 1) th pixel row A (n + 1). As the head 132 moves along the X direction, droplets are sequentially applied from each nozzle 135 to the pixel PX of the corresponding pixel row.

  Thereafter, the ejection amount of droplets ejected from each nozzle 135 is adjusted based on the spread state of the droplets applied to each pixel PX of the adjustment substrate SUB. That is, when the pixel rows are compared, if the spread state of the droplets is uniform, it can be determined that there is no variation in the discharge amount between the nozzles to which the droplets are applied. For example, as shown in FIG. In some cases, the pixel size at which a droplet spreading defect starts to occur varies from nozzle to nozzle.

  That is, for the n-th nozzle 135n, spreading failure starts to occur in the pixel PX having a pixel size of (1 + 4k) × a in the pixel row An, and for the (n + 1) -th nozzle 135 (n + 1), the pixel row A ( In (n + 1), a spreading defect starts to occur in the pixel PX having a pixel size of (1 + 2k) × a.

  Therefore, as a cause of such a defect, a case where the droplet discharge amount is adjusted for each nozzle will be described in consideration of variations in the droplet discharge amount between the nozzles. In the case of the result as shown in FIG. 7, at least the (n + 1) -th nozzle 135 is required in order to realize the coating accuracy required to spread uniformly to the pixel PX having a pixel size of (1 + 3k) × a. The discharge amount (n + 1) is increased. Such adjustment of the discharge amount of the droplet is performed by, for example, setting the voltage level applied to the piezoelectric element arranged corresponding to the nozzle 135 (n + 1) higher than the set value in the discharge mechanism 136 as shown in FIG. It is possible to control by changing or setting the pulse width of the pulse voltage to be larger than the set value.

  As a result, the liquid droplets ejected from the (n + 1) th nozzle 135 (n + 1) spread uniformly in the pixel PX, and the occurrence of a spreading defect that exposes the first electrode is suppressed. For this reason, when the second electrode is formed on the photoactive layer formed by the droplets, it is possible to prevent the first electrode and the second electrode from being short-circuited due to the droplet spreading failure. .

  Also, it is desirable to reduce the discharge amount for the nth nozzle 135n. That is, even if the droplets spread uniformly in the pixel PX of the target pixel size (1 + 3k) × a, if the amount of the droplets in the pixel PX differs for each nozzle, the first electrode and the second electrode This is not desirable because it causes a difference in the thickness of the photoactive layer held between them and may cause display defects such as display unevenness. For this reason, by reducing the droplet discharge amount for the n-th nozzle 135n, the pixel PX is filled with an appropriate amount of droplets, and the film thickness of the photoactive layer in each pixel is made uniform. Display quality can be improved.

<Second adjustment method>
In the second adjustment method, the dispersion of the landing positions of the droplets on the pixels between the nozzles is adjusted. First, as shown in FIG. 8, an adjustment substrate SUB having a plurality of pixel columns A in which a plurality of pixels PX having different pixel pitches at different levels and arranged in one direction, that is, the X direction is prepared. In the example shown here, each pixel PX has a quadrangular shape, and the pixel sizes are all the same size a. In the example shown in FIG. 8, the shape of the pixel PX is shown as a square. However, the shape of the pixel is not particularly limited to this example. However, the central symmetry is ensured by using a regular polygon or a circle. It is desirable.

  The center (center of gravity position) C of each pixel PX is as indicated by the intersection of the broken line and the solid line, and each pixel PX is arranged at a pitch P1 along the X direction. The pixel pitch P1 is different among the pixels, and is different from the uniform pitch P2 indicated by the broken line intersection. In the example shown in FIG. 8, for each pixel row A, the position of the pixel center C is shifted with respect to the coating pitch P2 under a plurality of conditions such as d, 2d, 3d,. At this time, the shift amount d is set to a small value with respect to the pixel pitch P1, but the magnitude is changed according to the accuracy of adjustment. The interval for shifting is not particularly limited to an interval such as d, 2d, 3d,. Further, in FIG. 8, the droplet landing position is adjusted with respect to the X direction. However, the adjustment can be made by preparing an adjustment substrate in which the pixel center position is similarly shifted with respect to the Y direction. is there. In this embodiment, the displacement of the landing position in the Y direction is adjusted by the angle θ that rotates the head 132 as shown in FIG. 5 in the XY plane.

  Droplets are applied from the nozzles 135 of the coating apparatus toward the pixels PX of the pixel rows A of the adjustment substrate SUB. That is, the nth nozzle row 135n is made to correspond to the nth pixel row An on the adjustment substrate SUB, and the (n + 1) th nozzle 135 (n + 1) is made to correspond to the (n + 1) th pixel row A (n + 1). As the head 132 moves along the X direction, droplets are sequentially applied from each nozzle 135 to the pixel PX of the corresponding pixel row.

  Thereafter, the landing position of each droplet discharged from each nozzle 135 on each pixel is adjusted based on the spread state of the droplets applied to each pixel PX on the adjustment substrate SUB. That is, when the pixel rows are compared, if the spread state of the droplets is uniform, it can be determined that there is no variation in the landing position between the nozzles to which the droplets are applied. For example, as shown in FIG. In some cases, the shift position at which a droplet spreading defect starts to occur varies from nozzle to nozzle.

  In other words, the n-th nozzle 135n is a pixel whose pixel pitch is shifted by d in the + X direction in the pixel row An, and spreads to the right side thereof, and a defect starts to occur, and the pixel pitch is shifted by 2d in the −X direction. It can be seen that a spreading failure has started to occur on the left side, and the spreading state of the droplet is uneven (that is, the landing position of the droplet is shifted in the −X direction).

  Further, regarding the (n + 1) th nozzle 135 (n + 1), in the pixel row A (n + 1), the pixel pitch is shifted by d in the −X direction, and a defect starts to occur on the left side. It can be seen that the state is non-uniform (that is, the landing position of the liquid droplet is shifted in the −X direction). Moreover, it can be seen that the landing position of the (n + 1) th nozzle 135 (n + 1) is larger in the −X direction than the nth nozzle 135n.

  Therefore, as a cause of such a failure, a case where the droplet discharge timing is adjusted for each nozzle will be described in consideration of variations in the landing positions of the droplets on the pixels between the nozzles. In the case of the result as shown in FIG. 9, in order to realize the coating accuracy required to be adjusted around the pixel whose shift amount is 0, the landing position of the nth nozzle 135n is shifted in the + X direction. Further, the landing position of the (n + 1) th nozzle 135 (n + 1) is shifted in the + X direction to be larger than the adjustment width of the nth nozzle 135n. Such adjustment of the landing position of the droplet is performed by applying a voltage applied to, for example, the piezoelectric element arranged corresponding to the nozzle 135n and the nozzle 135 (n + 1) in the discharge mechanism 136 as shown in FIG. This is possible by changing the discharge timing of the liquid droplets by control such as delaying from the set value.

  As a result, the liquid droplets ejected from the n-th nozzle 135n and the (n + 1) -th nozzle 135 (n + 1) toward the corresponding pixel PX land near the center position of the pixel PX, and the landing position between the nozzles Can be corrected. For this reason, it becomes possible to prevent the occurrence of a display defect such as a short circuit between the first electrode and the second electrode and display unevenness due to a droplet spreading defect.

<Adjustment mechanism>
Next, an adjustment mechanism applicable to the above-described coating apparatus will be described.

  That is, as shown in FIG. 10, the adjustment mechanism 140 causes the liquid droplets to be discharged from the nozzles toward the pixels of the pixel rows of the adjustment substrate SUB described in the first adjustment method and the second adjustment method as described above. After the application, the light source 141 that illuminates the adjustment substrate SUB to which the droplet has been applied, the imaging unit 142 that captures a reflection image of the droplet applied to the adjustment substrate SUB, and the image captured through the imaging unit 142 And an image analysis unit 143 for analyzing the above.

  As the light source 141, it is desirable to select a light source having a dominant wavelength in the absorption wavelength region of the droplet material exhibiting fluorescence. By adjusting the droplet application accuracy by measuring the fluorescence intensity in the adjustment mechanism 140, the adjustment mechanism 140 is less affected by variations in reflectance due to surface irregularities of the adjustment substrate SUB, and the adjustment accuracy can be improved. It is.

  The image analysis unit 143 can capture an image captured through the imaging unit 142, measure a reflection intensity profile, and measure a three-dimensional droplet distribution. First, items such as the center of gravity, the center of a circle, and the center of an ellipse can be measured at the same time, and the landing positions of the droplets can also be measured simultaneously.

  Further, the image analysis unit 143 calculates a droplet discharge amount and a discharge timing correction value for each nozzle based on such an analysis result, and controls the discharge mechanism 136. Thereby, in the coating apparatus, it is possible to construct a droplet discharge adjustment system that can improve the variation in the discharge amount between the nozzles and the variation in the landing position.

(Production method)
Next, a method for manufacturing the display device having the above-described configuration will be described. Here, it is assumed that the photoactive layer 64 is formed by a selective coating method using inkjet using a polymer material.

  That is, the wiring substrate 120 having the display area 102 having a total of 920,000 pixels of 480 pixels in the vertical direction and 640 × 3 (R, G, B) pixels in the repetition of the processes such as the formation of the metal film and the insulating film and the patterning. Prepare. Then, as shown in FIG. 11A, the first electrode 60 is formed for each pixel in the display area 102 on the wiring substrate 120. About the formation method of this 1st electrode 60, generally you may form by the photolithography process and may form by the mask sputtering method through the mask which has the pattern of a 1st electrode.

  Subsequently, as shown in FIG. 11B, a partition wall 70 exposing the first electrode 60 in the display area 102 is formed. That is, after a photosensitive resin material such as an acrylic type positive tone resist is formed and patterned by a general photolithography process, a baking process is performed at 220 ° C. for 30 minutes. Thereby, the partition wall 70 that separates the pixel rows of different colors adjacent to each other in the display area 102 is formed.

  Subsequently, as illustrated in FIG. 11C, a photoactive layer 64 including a light emitting layer that emits light in a corresponding color is formed on the first electrode 60 for each pixel of each pixel column. That is, first, in the coating apparatus 130, the droplet application accuracy is adjusted by applying the first adjustment method and the second adjustment method described above. Then, the wiring substrate 120 having the partition wall 70 is placed on the stage 131 of the coating apparatus 130. At this time, the wiring substrate 120 is positioned so that the extending direction of the pixel column in the wiring substrate 120 corresponds to the X direction in the coating device 130 and the direction orthogonal to the extending direction of the pixel column corresponds to the Y direction in the coating device 130. To do.

  Thereafter, a head 132 having a plurality of nozzles 135 is disposed opposite to the wiring substrate 120 to accommodate a droplet of a polymer material for forming a hole buffer layer in addition to a light emitting layer that emits light of a corresponding color. Apply for each pixel. This droplet application step is performed while scanning the head 132 in the X direction relative to the display area 102.

  As a result, a photoactive layer 64R is formed on each first electrode 60 of the red pixel column made up of red pixels. The photoactive layer 64G is formed on each first electrode 60 of the green pixel row composed of green pixels by the same coating method. The photoactive layer 64B is formed on each first electrode 60 of the blue pixel column composed of blue pixels by the same coating method.

  Subsequently, as shown in FIG. 11D, the second electrode 66 is formed so as to cover the photoactive layers 64 (R, G, B) of the respective color pixels in the display area 102. The second electrode 66 is preferably formed by a dry process so that the previously formed photoactive layer 64 (R, G, B) is not damaged by the influence of moisture. For example, the second electrode 66 is formed by vapor deposition. Is done.

  On the other hand, in order to seal the display area 102 on the array substrate 100, an ultraviolet curable sealant is applied along the outer periphery of the sealing body, and in an inert gas atmosphere such as nitrogen gas or argon gas, The array substrate 100 and the sealing body are bonded together. Thereby, the organic EL element 40 is enclosed in the sealed space of an inert gas atmosphere. Thereafter, the sealing material is cured by irradiating with ultraviolet rays.

  According to the manufacturing method described above, the amount of droplets can be averaged for each pixel by applying droplets to each pixel of the corresponding pixel row from each nozzle by a coating apparatus that has adjusted the coating accuracy. In addition, it was possible to prevent the spread failure of the droplets within the pixel. For this reason, a short circuit between the first electrode and the second electrode sandwiching the photoactive layer did not occur, and stripe-like display unevenness due to application unevenness was not confirmed.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

FIG. 1 is a diagram schematically showing a configuration of an organic EL display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a structure when the display area of the array substrate shown in FIG. 1 is cut in the Y direction. FIG. 3 is a diagram schematically showing the configuration of a coating apparatus applicable when forming the photoactive layer. FIG. 4 is a diagram schematically showing the structure of a head applicable to the coating apparatus shown in FIG. FIG. 5 is a diagram for explaining an adjustment method for adjusting the droplet application accuracy in the coating apparatus shown in FIG. 3. FIG. 6 is a diagram schematically showing a configuration of an adjustment substrate applicable in the first adjustment method. FIG. 7 is a view for explaining a first adjustment method applicable to the coating apparatus shown in FIG. FIG. 8 is a diagram schematically showing a configuration of an adjustment substrate applicable in the second adjustment method. FIG. 9 is a view for explaining a second adjustment method applicable to the coating apparatus shown in FIG. FIG. 10 is a diagram schematically showing a configuration of an adjustment mechanism applicable to the coating apparatus shown in FIG. FIG. 11A is a diagram for explaining a manufacturing process for forming an organic EL element, and shows a process for forming a first electrode. FIG. 11B is a diagram for explaining a manufacturing process for forming the organic EL element, and shows a process for forming a partition. FIG. 11C is a diagram for explaining a manufacturing process for forming the organic EL element, and shows a process for forming the photoactive layer. FIG. 11D is a diagram for explaining a manufacturing process for forming the organic EL element, and shows a process for forming the second electrode.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Organic EL display apparatus, 10 ... Pixel switch, 20 ... Drive transistor, 30 ... Storage capacitor element, 40 ... Organic EL element, 60 ... 1st electrode, 64 (R, G, B) ... Photoactive layer, 66 ... Second electrode, 70 ... partition wall, 100 ... array substrate, 102 ... display area, 120 ... wiring board, PX ... pixel, 130 ... coating device, 132 ... head, 135 ... nozzle, 136 ... discharge mechanism, 140 ... adjustment mechanism, 141 ... light source 142 ... imaging unit 143 ... image analysis unit SUB ... adjustment substrate

Claims (5)

In a coating apparatus including a plurality of nozzles for coating droplets for forming a photoactive layer held between a pair of electrodes,
Preparing an adjustment substrate having a plurality of pixel columns in which a plurality of pixels having different pixel sizes at different levels are arranged in one direction at an equal pitch;
A step of applying droplets from the nozzles of the coating apparatus toward the pixels of each pixel row of the adjustment substrate;
An adjustment step of adjusting the discharge amount of the droplets discharged from each nozzle based on the spread state of the droplets applied to each pixel of the adjustment substrate;
The adjustment method of the coating device characterized by the above-mentioned. In a coating apparatus including a plurality of nozzles for coating droplets for forming a photoactive layer held between a pair of electrodes,
Preparing an adjustment substrate including a plurality of pixel columns in which a plurality of pixels of equal sizes having different pixel pitches at different levels are arranged in one direction;
A step of applying droplets from the nozzles of the coating apparatus toward the pixels of each pixel row of the adjustment substrate;
An adjustment step of adjusting the landing position of each droplet discharged from each nozzle on each pixel based on the spread state of the droplet applied to each pixel of the adjustment substrate;
The adjustment method of the coating device characterized by the above-mentioned.   The adjustment step includes a step of imaging an adjustment substrate coated with a droplet, a step of detecting a pixel size at which a part of the pixel starts to cause a droplet spreading defect that is exposed from the droplet based on the captured image, and And a step of controlling a voltage applied to a discharge mechanism for discharging a droplet from each nozzle so that a pixel having a desired pixel size is filled with the droplet. The adjustment method of the coating device as described. A plurality of nozzles for applying droplets for forming a photoactive layer held between a pair of electrodes;
A discharge mechanism for discharging droplets from each nozzle;
A liquid crystal substrate is provided with an adjustment substrate having a plurality of pixel columns in which a plurality of pixels having different pixel areas at different levels and arranged in one direction at equal pitches, and droplets are respectively directed from the nozzles toward the pixels of the pixel columns of the adjustment substrate. An adjustment mechanism that adjusts the discharge amount of liquid droplets discharged from each nozzle by controlling the discharge mechanism based on the spread state of the liquid droplets applied to each pixel of the adjustment substrate,
A coating apparatus comprising: A plurality of nozzles for applying droplets for forming a photoactive layer held between a pair of electrodes;
A discharge mechanism for discharging droplets from each nozzle;
A liquid crystal substrate is provided with an adjustment substrate having a plurality of pixel rows in which a plurality of pixels of equal sizes having different pixel pitches at different levels are arranged in one direction, and droplets are respectively directed from each nozzle toward the pixels of each pixel row of the adjustment substrate. An adjustment mechanism that controls the ejection mechanism based on the spread state of the droplets applied to each pixel of the adjustment substrate to adjust the landing position of each droplet discharged from each nozzle on each pixel. ,
A coating apparatus comprising:

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