JP2006185790A - Electro-optical device, electronic apparatus and manufacturing method of electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device allowing a pixel constituent element having a certain thickness to be formed in each pixel regardless of a planar shape of the pixel. <P>SOLUTION: When an organic EL display device is manufactured, a single pixel 515 is divided into a plurality of sub-pixels 515a, 515b and 515c by barrier ribs 505. Then, in the sub-pixels 515a, 515b and 515c, a dimensional ratio in two directions perpendicular to each other is close to 1:1 relative to the pixel 515. A hole injection layer and a luminescent layer are formed in each of the sub-pixels 515a, 515b and 515c by jetting droplets MO of a liquid substance such as a hole injection layer formation material or a luminescent layer formation material from a droplet jetting head to the center of each of the sub-pixels 515a, 515b and 515c. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electro-optical device in which a large number of pixels are formed in a matrix, an electronic apparatus including the electro-optical device, and a method for manufacturing the electro-optical device. More specifically, the present invention relates to a film forming technique for forming a pixel component by discharging a droplet from a nozzle opening of an ejection head.

  Examples of display devices used in electronic devices such as mobile phones, personal computers, and PDAs (Personal Digital Assistants) include liquid crystal devices and electro-optical devices such as organic electroluminescence (EL / Electroluminescence) devices. In manufacturing these electro-optical devices, the formation of the color filter of the liquid crystal device, the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer, the light emitting layer, etc. It has been proposed to use the ink jet method employed in printers (see, for example, Patent Document 1).

In such an electro-optical device, the planar shape of each pixel is actually determined by the shape of the screen and the number of pixels in the vertical and horizontal directions of the screen. For example, in an organic EL device, FIG. ) And (B), the region (pixel 515) where the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer and the light emitting layer are to be formed is often an elongated rectangle. On the other hand, in the ink jet method, the droplet M0 is ejected from the nozzle opening of the ejection head and landed on the substrate, so that the shape is substantially circular. Accordingly, a plurality of droplets M0 are ejected from the ejection head into the pixel 515 by shifting their landing positions, and the droplet M0 is caused to flow and spread in the pixel 515, so that a hole injection layer and a hole transport are formed throughout the pixel 515. Pixel components such as a layer, an electron injection layer, an electron transport layer, and a light emitting layer are formed.
JP 2000-353594 A

  However, in a configuration in which droplets are ejected into an elongated region and spread over the entire region, the flow distance varies greatly depending on the direction of flow, so even if the landing position of the droplet is slightly shifted, the droplet can flow evenly. However, there is a problem that variations occur in the film thickness of the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer, the light emitting layer, and the like. Such variation is not preferable because luminance varies from pixel to pixel and image quality is degraded.

  In view of the above problems, an object of the present invention is to provide an electro-optical device capable of forming a pixel component having a certain thickness on each pixel regardless of the planar shape of the pixel, and a manufacturing method thereof.

  In order to solve the above-described problem, according to the present invention, in an electro-optical device in which a large number of pixels are formed in a matrix by a plurality of pixel components, the pixel has a dimensional ratio in two orthogonal directions that is 1 than that of the pixel. Is divided into a plurality of sub-pixels having a planar shape close to 1 and at least one of the plurality of pixel components is formed over the sub-pixels in a state of being divided into each of the plurality of sub-pixels. It is characterized by.

  In the present invention, each of the plurality of pixels has a planar shape of, for example, a rectangle, an oval, or an ellipse.

  In the present invention, it is preferable that each of the sub-pixels has a regular polygonal shape or a circular planar shape.

  In the present invention, it is preferable that the pixel is divided into the plurality of sub-pixels around the pixel and by partition walls in the pixel.

  In the present invention, the electro-optical device is, for example, a color EL display device. In this case, each of the plurality of pixels corresponds to a predetermined color. When the present invention is applied to such a color EL display device, among the plurality of pixel components, the pixel component formed by being divided into each of the sub-pixels is, for example, hole injection of a self-luminous element. A layer, a hole transport layer, an electron injection layer, an electron transport layer, or a light emitting layer.

  In the present invention, the electro-optical device is, for example, a color liquid crystal device. In this case, each of the plurality of pixels corresponds to a predetermined color. In the case where the present invention is applied to such a color liquid crystal device, among the plurality of pixel components, the pixel component formed by being divided into each of the sub-pixels is, for example, a color filter.

  In the present invention, the large number of pixels may have the same size for each color, and the number of divisions of the pixel into the sub-pixels may be the same for each color, but the large number of pixels have different sizes for each color, A configuration in which the number of divisions of the pixel into the sub-pixels is different between at least two colors may be employed.

  The present invention includes a droplet discharge step of discharging droplets from the nozzle openings of the discharge head to form at least one pixel component in each of a large number of pixels configured in a matrix on the electro-optical device substrate. In the electro-optical device manufacturing method, before performing the liquid droplet ejection step, the pixel is divided into a plurality of planar sub-pixels whose dimensional ratios in two orthogonal directions are closer to 1: 1 than the pixels. A step of discharging a droplet from the nozzle opening to each of the plurality of sub-pixels.

  In the present invention, in the dividing step, a partition that can prevent the liquid droplet from flowing out of the sub-pixel is formed around the pixel and in the pixel to divide the pixel into the plurality of sub-pixels. Is preferred.

  An electro-optical device to which the present invention is applied is used in an electronic apparatus such as a mobile phone, a personal computer, or a PDA.

  Hereinafter, an example of a droplet discharge device, an organic EL display device as an example of an electro-optical device, and a method for manufacturing the organic EL display device will be described with reference to the drawings.

(Overall configuration of droplet discharge device)
FIG. 1 is a perspective view showing the overall configuration of a droplet discharge apparatus used in the present invention. Note that when color printing or a color display device is manufactured by a droplet discharge device, it is usually necessary to form three color R, G, and B picture elements. Accordingly, with regard to the droplet discharge device, one unit can be configured to discharge droplets corresponding to each color, or a plurality of units corresponding to a predetermined color are prepared. One of the plurality of prepared droplet discharge devices will be described.

  In FIG. 1, a droplet discharge device 10 discharges various liquid materials as droplets to desired positions on a workpiece such as a substrate, and includes a plurality of nozzles that discharge liquid materials as droplets onto various workpieces. Liquid droplet ejection heads 22 and a common carriage 26 for holding these liquid droplet ejection heads 22. The droplet discharge device 10 includes a head position control device 17 that controls the position of the droplet discharge head 22, a substrate position control device 18 that controls the position of the substrate 12 as a workpiece, and the droplet discharge head 22 as a substrate. A main scanning drive unit 19 as a main scanning driving unit for main scanning movement with respect to 12, a sub scanning driving unit 21 as a sub scanning driving unit for moving the droplet discharge head 22 with respect to the substrate 12, and a substrate 12 is provided with a substrate supply device 23 for supplying 12 to a predetermined work position in the droplet discharge device 10 and a control device 24 for controlling the droplet discharge device 10 in general. The position control device 18, the main scanning drive device 19, and the sub-scanning drive device 21 constitute moving means for relatively moving the droplet discharge head 22 (carriage 26) and the substrate 12. There. The head position control device 17, the substrate position control device 18, the main scanning drive device 19, and the sub-scanning drive device 21 are installed on the base 9, and each of these devices is covered with a cover 14 as necessary.

  The head position control device 17 includes an α motor (not shown) that rotates the droplet discharge head 22 in-plane, and a β motor that swings and rotates the droplet discharge head 22 about an axis parallel to the sub-scanning direction Y (see FIG. A γ motor (not shown) that swings and rotates the droplet discharge head 22 about an axis parallel to the main scanning direction, and a Z motor that translates the droplet discharge head 22 in the vertical direction (not shown). Not shown). The substrate position control device 18 includes a table 49 on which the substrate 12 is placed, and a θ motor (not shown) that rotates the table 49 in-plane. The main scanning drive device 19 includes an X guide rail 52 extending in the main scanning direction X, and an X slider 53 incorporating a pulse-driven linear motor. The X slider 53 translates in the main scanning direction along the X guide rail 52 when the built-in linear motor operates. The sub-scanning driving device 21 includes a Y guide rail (not shown) extending in the sub-scanning direction Y and a Y slider 56 incorporating a pulse-driven linear motor. The Y slider 56 translates in the sub-scanning direction Y along the Y guide rail when the built-in linear motor operates. The linear motor that is pulse-driven in the X slider 53 and the Y slider 56 can finely control the rotation angle of the output shaft by the pulse signal supplied to the motor. Therefore, the droplet supported by the X slider 53 The position of the ejection head 22 in the main scanning direction X and the position of the table 49 in the sub-scanning direction Y can be controlled with high definition. The position control of the droplet discharge head 22 and the table 49 is not limited to the position control using the pulse motor, and can be realized by feedback control using a servo motor or any other control method.

  The substrate supply device 23 includes a substrate accommodating portion 57 that accommodates the substrate 12 and a robot 58 that conveys the substrate 12. The robot 58 includes a base 59 placed on an installation surface such as a floor, the ground, a lift shaft 61 that moves up and down relative to the base 59, a first arm 62 that rotates about the lift shaft 61, and a first arm. A second arm 63 that rotates with respect to 62 and a suction pad 64 provided on the lower surface of the front end of the second arm 63 are provided. The suction pad 64 can suck the substrate 12 by air suction or the like.

  A head camera 79 that moves integrally with the droplet discharge head 22 is disposed in the vicinity of the droplet discharge head 22. A support device (not shown) provided on the base 9 is provided with a substrate camera (not shown), and the substrate camera can photograph the substrate 12.

  Here, a capping mechanism 76 and a cleaning mechanism 77 are arranged under the trajectory of the droplet discharge head 22 that is driven by the main scanning driving device 19 and moves in the main scanning direction, at one side of the sub-scanning driving device 21. The capping mechanism 76 is a mechanism for preventing the nozzle from drying when the droplet discharge head 22 is in a standby state. The cleaning mechanism 77 is a mechanism for cleaning the droplet discharge head 22. In addition, an electronic balance 78 for measuring the weight of droplets ejected from the individual nozzles 27 in the droplet ejection head 22 is disposed at the other side position of the sub-scanning drive device 21.

(Configuration of droplet discharge head)
2A, 2 </ b> B, 2 </ b> C, and 2 </ b> D are explanatory diagrams showing the configuration of the droplet discharge head 22, explanatory diagrams schematically showing the internal structure of the droplet discharge head 22, and flexural vibration, respectively. It is explanatory drawing of the pressure generating element of mode, and explanatory drawing of the pressure generating element of longitudinal vibration mode. Note that a plurality of droplet discharge heads 22 are held by a common carriage 26, but since they basically have the same configuration, one of them will be described as an example.

  As shown in FIG. 2A, the droplet discharge head 22 includes a nozzle row 28 formed by arranging a large number of nozzle openings 27 in a row. The number of nozzle openings 27 is, for example, 180, the hole diameter of the nozzle openings 27 is, for example, 28 μm, and the nozzle pitch between the nozzle openings 27 is, for example, 141 μm. The main scanning direction X of the droplet discharge head 22 with respect to the substrate 12 and the sub-scanning direction Y orthogonal thereto are as illustrated. That is, the droplet discharge head 22 is positioned so that the nozzle row 28 extends in a direction intersecting with the main scanning direction X, and the liquid material is transferred to the plurality of nozzle openings 27 while moving in parallel in the main scanning direction X. The liquid droplets are made to land at a predetermined position in the substrate 12 by selectively ejecting them. Further, the droplet discharge head 22 can be moved in parallel in the sub-scanning direction Y by a predetermined distance, so that the main scanning position by the droplet discharge head 22 can be shifted at a predetermined interval.

  As shown in FIGS. 2B and 2C, the droplet discharge head 22 includes, for example, a stainless steel nozzle plate 29, an elastic plate 31 opposed thereto, and a plurality of partition members 32 that join them together. have. A plurality of pressure generating chambers 33 and a liquid reservoir 34 are formed between the nozzle plate 29 and the elastic plate 31 by the partition member 32, and the plurality of pressure generating chambers 33 and the liquid reservoir 34 are connected via a liquid flow inlet 38. Communicate with each other. A liquid material supply hole 36 is formed at an appropriate position of the elastic plate 31, and a liquid material supply device 37 is connected to the liquid material supply hole 36. The liquid material supply device 37 supplies the liquid material M to be discharged to the liquid material supply hole 36. The supplied liquid material M fills the liquid reservoir 34, and further fills the pressure generating chamber 33 through the liquid flow inlet 38.

  The nozzle plate 29 is provided with a nozzle opening 27 for ejecting the liquid M from the pressure generating chamber 33 as a droplet M0, and the nozzle forming surface 271 where the nozzle opening 27 is open is a flat surface. ing. A pressure generating element 39 is attached to the back surface of the surface of the elastic plate 31 forming the pressure generating chamber 33 so as to correspond to the pressure generating chamber 33. The pressure generating element 39 is a piezoelectric element in a flexural vibration mode including a piezoelectric element 41 and a pair of electrodes 42 a and 42 b that sandwich the piezoelectric element 11. The vibration direction is indicated by an arrow C.

  As shown in FIG. 2D, the pressure generating element 39 may be a longitudinal vibration mode piezoelectric element. This longitudinal vibration mode piezoelectric element (pressure generating element 39) is configured by alternately laminating piezoelectric materials and conductive materials in parallel to the extension direction, with the tip fixed to the elastic plate 31 and the other end based on the base. It is fixed to the base 20. Such a pressure generating element 39 contracts in a direction perpendicular to the stacking direction of the conductive layers in a charged state, and extends in a direction perpendicular to the conductive layer when the charged state is released.

  When any piezoelectric element is used, it is deformed by a drive signal applied between the electrodes, and the pressure generating chamber 33 is expanded and contracted. In addition, a liquid repellent layer 43 made of, for example, a Ni-tetrafluoroethylene eutectoid plating layer is provided around the nozzle opening 27 in order to prevent the flying of the droplet M0 and the clogging of the nozzle opening 27. It is done.

[Configuration of electro-optical device and outline of manufacturing method]
As an example of an electro-optical device, a configuration of an organic EL display device and a manufacturing process thereof will be described. FIG. 3 is a block diagram showing an electrical configuration of an organic EL display device including an EL element using a charge injection type organic thin film as an electro-optical material. FIG. 4 is a manufacturing process cross-sectional view showing the steps of the manufacturing process of the organic EL display device, and corresponds to a cross section of one pixel of the organic EL display device.

  In FIG. 3, an organic EL display device 500 is a display device that drives and controls an EL element that emits light when a drive current flows through an organic semiconductor film, and any of the light-emitting elements used in this type of display device is self. Since it emits light, there is an advantage that a backlight is not required and the viewing angle dependency is small. In the electro-optical device 500 shown here, a plurality of scanning lines 563, a plurality of data lines 564 extending in a direction intersecting the extending direction of the scanning lines 563, and the data lines 564 are arranged in parallel. A plurality of common power supply lines 505 and pixels 515 corresponding to the intersections of the data lines 564 and the scanning lines 563 are configured, and the pixels 515 are arranged in a matrix in the image display area. A data line driving circuit 551 including a shift register, a level shifter, a video line, and an analog switch is configured for the data line 564. A scanning line driving circuit 554 including a shift register and a level shifter is configured for the scanning line 563. Each pixel 515 includes a switching thin film transistor 509 to which a scanning signal is supplied to the gate electrode through the scanning line 563 and a storage capacitor for holding an image signal supplied from the data line 564 through the switching thin film transistor 509. 533, a current thin film transistor 510 to which an image signal held by the storage capacitor 533 is supplied to the gate electrode, and a drive current from the common power supply line 505 when electrically connected to the common power supply line 505 via the current thin film transistor 510. The light emitting element 513 into which the liquid flows is configured. The light-emitting element 513 includes a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an organic semiconductor film as an organic EL material layer, a metal film such as lithium-containing aluminum and calcium on the upper side of the pixel electrode. The counter electrode is made up of a plurality of pixels 515 across the data line 564 and the like. Here, when performing color display on the organic EL display device 500, each pixel 515 is made to correspond to red (R), green (G), and blue (B).

  In order to manufacture the organic EL display device 500 having such a configuration, a substrate is prepared. Here, in the organic EL display device 500, light emitted from a light emitting layer to be described later can be extracted from the substrate side, and can be configured to be extracted from the side opposite to the substrate. In the case where the emitted light is extracted from the substrate side, a transparent or translucent material such as glass, quartz, or resin is used as the substrate material, and glass is particularly preferably used. Alternatively, a color filter film, a color conversion film containing a fluorescent material, or a dielectric reflection film may be disposed on the substrate to control the emission color. In the case where the emitted light is extracted from the side opposite to the substrate, the substrate may be opaque. In that case, a ceramic sheet such as alumina, a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation, A curable resin, a thermoplastic resin, or the like can be used.

  In this example, as shown in FIG. 4A, a transparent substrate 502 made of glass (corresponding to the substrate 12 shown in FIG. 1) is prepared as a substrate, and TEOS (corresponding to the transparent substrate 502 as needed). A base protective film (not shown) made of a silicon oxide film having a thickness of about 200 to 500 nm is formed by a plasma CVD method using tetraethoxysilane) or oxygen gas as a raw material.

Next, the temperature of the transparent substrate 502 is set to about 350 ° C., and a semiconductor film 520a made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the base protective film by plasma CVD. Next, a crystallization process such as laser annealing or solid phase growth is performed on the semiconductor film 520a to crystallize the semiconductor film 520a into a polysilicon film. In the laser annealing method, a line beam having a beam length of 400 mm is used with, for example, an excimer laser, and the output intensity is set to, for example, 200 mJ / cm ² . With respect to the line beam, the line beam is scanned so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.

  Next, as shown in FIG. 4B, the semiconductor film (polysilicon film) 520a is patterned to form an island-shaped semiconductor film 520b, and a plasma CVD method using TEOS, oxygen gas, or the like as a raw material on the surface thereof. As a result, a gate insulating film 521a made of a silicon oxide film or a nitride film having a thickness of about 60 to 150 nm is formed. Note that the semiconductor film 520b serves as a channel region and a source / drain region of the current thin film transistor 510 illustrated in FIG. 3, but a semiconductor film serving as a channel region and a source / drain region of the switching thin film transistor 509 at different cross-sectional positions. Is also formed. That is, in the organic EL display device 500, two types of transistors 509 and 510 are formed at the same time or between different layers, but are manufactured in the same procedure. Therefore, in the following description, only the current thin film transistor 510 will be described. Description of the switching thin film transistor 509 is omitted.

  Next, as shown in FIG. 4C, after a conductive film made of a metal film such as aluminum, tantalum, molybdenum, titanium, or tungsten is formed by sputtering, this is patterned to form a gate electrode 510g. Next, high-concentration phosphorus ions are implanted in this state, and source / drain regions 510a and 510b are formed in the semiconductor film 520b in a self-aligned manner with respect to the gate electrode 510g. Note that a portion where impurities are not introduced becomes a channel region 510c.

  Next, as illustrated in FIG. 4D, after an interlayer insulating film 522 is formed, contact holes 523 and 524 are formed, and relay electrodes 526 and 527 are embedded in the contact holes 523 and 524. Next, a signal line, a common power supply line, and a scanning line (not shown) are formed over the interlayer insulating film 522. Here, the relay electrode 527 and each wiring may be formed in the same process, and in this case, the relay electrode 526 is formed of an ITO film described later.

  Next, as illustrated in FIG. 4E, an interlayer insulating film 530 is formed so as to cover the upper surface of each wiring, and then a contact hole 532 is formed in the interlayer insulating film 530 at a position corresponding to the relay electrode 526. To do.

  Next, in the pixel electrode forming step, an ITO film is formed so as to fill the contact hole 532, and the ITO film is patterned, and a source / source line is formed at a predetermined position surrounded by the signal line, the common power supply line, and the scanning line. A pixel electrode 511 that is electrically connected to the drain region 510a is formed. Here, a portion sandwiched between the signal line, the common power supply line, and the scanning line is a place where a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and a light emitting layer, which will be described later, are formed.

  Next, in the partition formation step illustrated in FIG. 4F, the partition 505 is formed so as to surround a formation place of the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer, and the light emitting layer. The partition 505 functions as a partition member, and is formed of, for example, an insulating organic material such as acrylic resin or polyimide resin, or an insulating inorganic material such as polysilazane. About the film thickness of the partition 505, it forms so that it may become the height of 1-2 micrometers, for example. Further, the partition wall 505 is preferably one that exhibits liquid repellency with respect to the liquid material discharged from the droplet discharge head 22 described above.

  In order to make the partition 505 exhibit liquid repellency, for example, a method of treating the surface of the partition 505 with a fluorine compound or the like is employed. Examples of the fluorine compound include CF4, SF5, and CHF3. Examples of the surface treatment include plasma treatment and UV irradiation treatment. In this way, the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer and the light emitting layer are formed at a place, that is, between the application position of these forming materials and the surrounding partition 505. A sufficiently high step 535 is formed.

  Next, in the first droplet discharge step shown in FIG. 4G, with the upper surface of the transparent substrate 502 facing upward, the hole injection layer forming material 540a is removed from the droplet discharge device 10 described above. From the droplet discharge head 22, the liquid is selectively applied to an application position surrounded by the partition 505, that is, in the partition 505. At that time, the hole injection layer forming material 540a tends to spread in the horizontal direction because of its high fluidity, but since the partition wall 505 is formed surrounding the applied position, the hole injection layer forming material 540a It does not extend beyond the partition wall 505. Here, as the hole injection layer forming material 540a, for example, 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), which is a polyolefin derivative, is used as a hole injection material, and this is mainly composed of an organic solvent. A dispersion liquid dispersed as a solvent is preferably used. However, the hole injecting material is not limited to those described above, but polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) ) Cyclohexane, tris (8-hydroxyquinolinol) aluminum and the like can also be used.

  In this way, after the hole injection layer forming material 540a is discharged from the droplet discharge head 34 and disposed at a predetermined position, the liquid hole injection layer forming material 540a is dried to form the hole injection layer. The dispersion medium in the material 540a is evaporated. As a result, as shown in FIG. 4H, a solid hole injection layer 513a (pixel constituent element) is formed over the pixel electrode 511.

  Next, in the second droplet discharge process shown in FIG. 4I, the liquid droplet is discharged from the droplet discharge head 22 of the droplet discharge apparatus 10 described above with the upper surface of the transparent substrate 502 facing upward. A light emitting layer forming material 540 b is selectively applied on the hole injection layer 513 a in the partition 505. As the light emitting material, for example, a polymer material having a molecular weight of 1000 or more is used. Specifically, a polyfluorene derivative, a polyphenylene derivative, a polyvinyl carbazole, a polythiophene derivative, or a polymer material thereof, a perylene dye, a coumarin dye, a rhodamine dye such as rubrene, perylene, 9,10-diphenylanthracene, What doped tetraphenyl butadiene, Nile red, coumarin 6, quinacridone, etc. is used. As such a polymer material, a π-conjugated polymer material in which π electrons of a double bond are non-polarized on a polymer chain is also a conductive polymer, and thus has excellent light emitting performance. Preferably used. In particular, a compound having a fluorene skeleton in the molecule, that is, a polyfluorene compound is more preferably used. In addition to such materials, for example, a composition for an organic EL device disclosed in JP-A-11-40358, that is, a precursor of a conjugated polymer organic compound, and at least one kind for changing light emission characteristics A composition for an organic EL device comprising the above fluorescent dye can also be used as a light emitting layer forming material. As an organic solvent for dissolving or dispersing such a light emitting material, a nonpolar solvent is preferable. In particular, since the light emitting layer is formed on the hole injection layer 513a, Insoluble materials are used. Specifically, xylene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene and the like are preferably used. Note that the formation of the light emitting layer by discharging the light emitting layer forming material 540b includes a light emitting layer forming material that emits red colored light, a light emitting layer forming material that emits green colored light, and a light emitting that emits blue colored light. The layer forming material is discharged and applied to the corresponding pixels. Further, the pixels corresponding to the respective colors are determined in advance so that they are regularly arranged.

  After discharging the light emitting layer forming material 540b of each color in this way, the liquid light emitting layer forming material 540b is dried to evaporate the dispersion medium in the light emitting layer forming material 540b. As a result, as shown in FIG. 4J, a solid light-emitting layer 513b (pixel constituent element) is formed over the hole injection layer 513a. Thus, a light emitting element 513 including the hole injection layer 513a and the light emitting layer 513b is obtained.

  In addition, about the drying process of the forming material 540b, it is preferable to dry by heating at the temperature below the glass transition point of the forming material 540b, for example, the temperature of less than 100 degrees. By drying at such a temperature, the evaporation rate of the solvent in the forming material 540b can be kept relatively low, and the flow due to liquefaction of the forming material 540b can also be suppressed. As a result, the resulting light emitting layer 513b can also be sufficiently flattened. In addition, thermal damage caused by the drying process during the formation of the light emitting layer is reduced not only for the light emitting layer 513b but also for the hole injection layer 513a, so that a decrease in display performance due to a decrease in initial luminance or the like is suppressed. Here, in the case where a hole transport layer, an electron injection layer, and an electron transport layer are formed in addition to the hole injection layer 513a and the light emitting layer 513b, they can be formed by the same method, and thus description thereof is omitted. To do.

  Next, as shown in FIG. 4 (K), LiF / Al (a laminated film of LiF and Al), MgAg, or LiF / Ca / Al (LiF and Ca) are formed on the entire surface of the transparent substrate 502 or in the form of stripes. A counter electrode 512 is formed by depositing a film of Al and Al) by a vapor deposition method or the like. Then, after sealing, the organic EL display apparatus 500 (electro-optical apparatus) provided with the organic EL element is manufactured by further forming various elements such as wiring.

(Sub-pixel configuration)
5A and 5B are a perspective view and a plan view, respectively, showing a pixel electrode forming step in the organic EL display device to which the present invention is applied. 6A and 6B are a perspective view and a plan view, respectively, showing a partition wall forming step (dividing step) in the organic EL display device to which the present invention is applied. 7A and 7B are a perspective view and a plan view, respectively, showing a first droplet discharge process in the organic EL display device to which the present invention is applied. 8A and 8B are a perspective view and a plan view, respectively, showing a second droplet discharge process in the organic EL display device to which the present invention is applied.

  In this embodiment, when manufacturing the organic EL display device 500, first, in the pixel electrode formation step shown in FIG. 4E, as shown in FIGS. The rectangular pixel electrodes 511 whose planar shape is elongated are formed in a matrix. Therefore, in the organic EL display device 500, the pixel 515 having a long and narrow planar shape is formed.

  Then, the first droplet discharge step shown in FIG. 4G and the partition formation step before the second droplet discharge step shown in FIG. 4H (see FIG. 4F) are divided. As a process, as illustrated in FIGS. 6A and 6B, a partition 505 is formed so as to surround the pixel 515, and the partition 505 is also formed in the pixel 515, so that one pixel 515 includes a plurality of subpixels. In this embodiment, the pixel is divided into three sub-pixels 515a, 515b, and 515c.

  Here, the pixel 515 has an elongated rectangular planar shape, but the sub-pixels 515a, 515b, and 515c generally have a square planar shape, and the sub-pixels 515a, 515b and 515c have two orthogonal directions ( For example, the dimensional ratio in the directions indicated by arrows A and B in FIGS. 6A and 6B is closer to 1: 1 than the pixels 515. Note that the planar shape of the sub-pixels 515a, 515b, and 515c is not limited to a square, and may be a regular polygon such as a regular hexagon or a regular octagon. From the viewpoint of bringing the dimensional ratio in the two orthogonal directions closer to 1: 1, it is preferably a regular polygon, but if the dimension in the two orthogonal directions is closer to 1: 1 than the pixel 515, each Polygons with different side lengths may be used. Note that the size of the sub-pixels 515a, 515b, and 515c may be set to an optimum size depending on the size of the droplet M0 ejected from the droplet ejection head 22, and in this embodiment, one side is set to 1 μm to 1 mm. ing.

  After the pixel 515 is divided into a plurality of sub-pixels 515a, 515b, and 515c in this manner, in the first droplet discharge step shown in FIG. 4G, the hole injection layer forming material 540a is used as the above-described droplet. The droplet M0 is ejected from the droplet ejection head 22 of the ejection apparatus 10 to the center position of each of the sub-pixels 515a, 515b, and 515c surrounded by the partition 505, as shown by a one-dot chain line circle in FIG. . As a result, the hole injection layer forming material 540a extends to every corner of the sub-pixels 515a, 515b, and 515c, as shown in FIGS. Therefore, when the dispersion medium in the forming material 540a is evaporated by the drying process, the hole injection layer 513a (pixel constituent element) is formed on the pixel electrode 511 in a certain thickness in each of the subpixels 515a, 515b, and 515c. Can be formed.

  Next, in the second droplet discharge step shown in FIG. 4H, the light emitting layer forming material 540b is transferred from the droplet discharge head 22 of the droplet discharge device 10 to the droplet M0 shown in FIG. Is ejected to the center position of each of the sub-pixels 515a, 515b, and 515c surrounded by the partition 505, as indicated by a dashed-dotted circle. As a result, the light emitting layer forming material 540b extends to every corner of the sub-pixels 515a, 515b, and 515c, as shown in FIGS. Therefore, when the dispersion medium in the light emitting layer forming material 540b is evaporated by the drying process, the light emitting layer 513b (pixel constituent element) is formed on the hole injection layer 513a to have a certain thickness in each of the sub pixels 515a, 515b, and 515c. It can be formed.

  Note that in the case of forming a hole transport layer, an electron injection layer, and an electron transport layer in addition to the hole injection layer 513a and the light-emitting layer 513b, the description can be omitted because they can be formed by the same method. .

  Thereafter, as described with reference to FIG. 4K, LiF / Al (a laminated film of LiF and Al), MgAg, or LiF / Ca is formed on the entire surface of the transparent substrate 502 or in the form of stripes. / Al (a laminated film of LiF, Ca, and Al) is formed by a vapor deposition method or the like, and the counter electrode 512 is formed. Then, after sealing, the organic EL display apparatus 500 (electro-optical apparatus) provided with the organic EL element is manufactured by further forming various elements such as wiring.

  Accordingly, in the organic EL display device 500 of this embodiment, one pixel 515 is formed with three sub-pixels 515a, 515b, and 515c that share the current thin film transistor 510, the switching thin film transistor 509, the pixel electrode 511, the counter electrode 512, and the like. Each of the subpixels 515a, 515b, and 515c has a light emitting element 513 provided with a hole injection layer 513a and a light emitting layer 513b.

(Main effects of this form)
In the organic EL display device 500 configured as described above, the subpixels 515a, 515b, and 515c have two orthogonal directions (for example, the direction indicated by the arrow A in FIGS. 6A and 6B and the direction indicated by the arrow B). ) Is closer to 1: 1 than the pixel 515. Therefore, the hole injection layer forming material 540a discharged in the first droplet discharging step and the light emitting layer forming material 540b discharged in the second droplet discharging step flow in the subpixels 515a, 515b, and 515c. The flow distance is almost the same in any direction. Therefore, even if the landing position of the hole injection layer forming material 540a in the sub-pixels 515a, 515b and 515c or the landing position of the light-emitting layer forming material 540b in the sub-pixels 515a, 515b and 515c is slightly shifted, hole injection is performed. Since the layer forming material 540a and the light emitting layer forming material 540b spread with a uniform thickness to every corner in the sub-pixels 515a, 515b, and 515c, in any of the sub-pixels 515a, 515b, and 515c, hole injection in the sub-pixels is performed. There is almost no variation in the thickness of the layer 513a and the variation in the thickness of the light emitting layer 513b in the sub-pixel. Therefore, in any of the subpixels 515a, 515b, and 515c, there is no luminance variation within the subpixel, and there is no luminance variation within the pixel 511. Therefore, since light having a predetermined luminance is emitted from all the pixels 515, a high-quality image can be displayed.

  Further, according to the present embodiment, only the formation pattern of the partition 505 in the partition formation process is changed, and the ejection head 22 can originally eject the droplet M0 to an arbitrary position. Even when the pixels are divided into the pixels 515a, 515b, and 515c, the number of manufacturing steps does not increase.

(Modification 1)
In the above embodiment, the pixel 515 having a long planar shape is divided into the sub-pixels 515a, 515b, and 515c having a square planar shape by the partition wall 505. However, as shown in FIG. The partition 505 may divide the pixel 515 into sub-pixels 515a, 515b, and 515c having a circular planar shape.

  In such a configuration, the subpixels 515a, 515b, and 515c have a completely dimensional ratio of 1: 1 in two orthogonal directions (for example, the direction indicated by arrow A and the direction indicated by arrow B in FIG. 9). It is. Therefore, the hole injection layer forming material 540a (see FIG. 4G) discharged in the first droplet discharge process and the sub-pixels 515a, 515b, and 515c are discharged in the center position in the second droplet discharge process. When the light emitting layer forming material 540b (see FIG. 4I) flows and spreads in the sub-pixels 515a, 515b, and 515c, the flow distance is substantially the same in any direction. Therefore, even if the landing position of the hole injection layer forming material 540a in the subpixels 515a, 515b, and 515c or the landing position of the light emitting layer forming material 540b in the subpixels 515a, 515b and 515c is slightly shifted, the hole injection is performed. The layer forming material 540a and the light emitting layer forming material 540b are applied to the subpixels 515a, 515b, and 515c with a uniform thickness all the way.

(Modification 2)
In the above embodiment, the example in which the pixels 515 corresponding to red (R), green (G), and blue (B) have the same area and the same number of divisions has been described, but red (R), green ( The present invention may be applied when the areas of the pixels 515 corresponding to G) and blue (B) are different between colors. For example, since red (R), green (G), and blue (B) have the highest visibility of green (G), as shown in FIG. 10, a pixel 515 (R) corresponding to green (R) is added. , The width may be narrower than the pixels 515 (R) and 515 (B) corresponding to red (R) and blue (B). In such a case, for example, the pixels 515 (R) and 515 (B) corresponding to red (R) and blue (B) are divided into three square sub-pixels 515 a, 515 b and 515 c by the partition 505. The pixel 515 (R) corresponding to green (R) may be divided into four square sub-pixels 515 a ′, 515 b ′, 515 c ′ and 515 d ′ by the partition 505.

  In addition, since the light emission intensity is different in each light emitting element 513 corresponding to red (R), green (G), and blue (B), the area of the pixel 511 may be different between two colors or three colors. However, even in such a case, as described with reference to FIG. 10, the number of divisions is different between colors, and each color has two orthogonal directions (for example, indicated by an arrow A in FIG. 10). It is only necessary to form sub-pixels having a dimensional ratio close to 1: 1 in the direction and the direction indicated by arrow B).

(Other application examples)
In the above embodiment, each of the large number of pixels has a rectangular planar shape. However, the present invention may be applied to a case where the pixel has an elliptical or elliptical planar shape. Moreover, although the said form was an example which applied this invention to the organic electroluminescence display, you may apply this invention to an inorganic electroluminescence display. Furthermore, the present invention may be applied to a color liquid crystal device. Such a liquid crystal device is not shown, but a color filter (pixel constituent element) is formed in a matrix on one of a pair of substrates that hold liquid crystal. Therefore, when forming a color filter, the color filter forming material containing a predetermined color pigment or dye may be discharged as droplets from the droplet discharge head 22 of the droplet discharge device 10 described above. At that time, since the pixels are often formed in a rectangle in the liquid crystal device, such pixels are also divided into a plurality of sub-pixels by the partition walls as described with reference to FIG. 6, FIG. 9 or FIG. do it.

  In the above embodiment, the partition is used to divide the pixel into a plurality of sub-pixels. However, for example, one pixel may be divided into a plurality of sub-pixels by a linear liquid repellent region. With this configuration, when a droplet is ejected to the center position of the plurality of sub-pixels, the droplet does not get over the liquid-repellent region and spread to adjacent sub-pixels. Accordingly, the liquid droplets that have landed on each sub-pixel flow and spread only within the corresponding sub-pixel, so that the same effect as a partition is exhibited.

  Furthermore, in the above embodiment, since subpixels belonging to the same pixel may be driven under the same conditions, one pixel electrode is formed for one pixel and the pixel electrode is shared between subpixels. A configuration in which a pixel electrode is formed for each pixel may be employed. In this case, since the subpixels belonging to one pixel may be driven under the same conditions, a common pixel switching element may be provided for a plurality of pixel electrodes belonging to one pixel, and pixel switching is performed for each pixel electrode. An element may be provided.

  The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and the specific materials and configurations described in the embodiment are included. These are merely examples, and can be changed as appropriate. Therefore, the present invention is applied to various electro-optical devices such as plasma display devices, electrophoretic display devices, devices using electron-emitting devices (Field Emission Display, Surface-Conduction Electron-Emitter Display, etc.) in addition to EL display devices and liquid crystal devices May be applied. In addition, the electro-optical device to which the present invention is applied can be used as a display device in various electronic devices such as a mobile phone, a personal computer, and a PDA.

It is a perspective view which shows the whole structure of the droplet discharge apparatus used by this invention. (A), (B), (C), and (D) are explanatory views showing the configuration of the droplet discharge head used in the droplet discharge apparatus shown in FIG. 1, respectively, and schematically show the internal structure of the droplet discharge head. FIG. 2 is an explanatory diagram of a pressure generating element in a flexural vibration mode, and an explanatory diagram of a pressure generating element in a longitudinal vibration mode. It is a block diagram which shows the electric constitution of an organic electroluminescence display. It is sectional drawing which shows the procedure of the manufacturing process of an organic electroluminescence display. (A), (B) is the perspective view and top view which respectively show the pixel electrode formation process in the organic electroluminescence display to which this invention is applied. (A), (B) is the perspective view and top view which respectively show the partition formation process (division | segmentation process) in the organic electroluminescence display to which this invention is applied. (A) and (B) are a perspective view and a plan view, respectively, showing a first droplet discharge step in an organic EL display device to which the present invention is applied. (A) and (B) are a perspective view and a plan view, respectively, showing a second droplet discharge step in the organic EL display device to which the present invention is applied. It is a top view which shows the state which divided | segmented the pixel into the several sub pixel in the organic electroluminescent display apparatus which concerns on the modification 1 of this invention. It is a top view which shows the state which divided | segmented the pixel into the several sub pixel in the organic electroluminescent display apparatus which concerns on the modification 2 of this invention. It is the perspective view and top view which show the pixel structure of the conventional organic electroluminescence display.

Explanation of symbols

10 droplet ejection device, 22 droplet ejection head, 27 nozzle opening, 500 organic EL display device, 505 partition, 511 pixel electrode, 513a hole injection layer, 513b light emitting layer, 513 light emitting element, 515 pixel, 515a, 515b, 515c subpixel

Claims (10)

In an electro-optical device in which a large number of pixels are formed in a matrix by a plurality of pixel components,
The pixel is divided into a plurality of sub-pixels having a planar shape whose dimensional ratio in two orthogonal directions is closer to 1: 1 than the pixel,
An electro-optical device, wherein at least one of the plurality of pixel components is formed on the entire sub-pixel in a state of being divided into each of the plurality of sub-pixels.   2. The electro-optical device according to claim 1, wherein each of the plurality of pixels has a rectangular, oval or elliptical planar shape.   3. The electro-optical device according to claim 1, wherein each of the sub-pixels has a substantially polygonal or circular planar shape.   4. The electro-optical device according to claim 1, wherein the pixel is divided into the plurality of sub-pixels around the pixel and by a partition in the pixel.   5. The pixel component according to claim 1, wherein each of the plurality of pixels corresponds to a predetermined color, and is divided into each of the sub-pixels among the plurality of pixel components. Is an electro-optical device that is at least one of a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and a light-emitting layer of an electroluminescence element for an electroluminescence display device.   5. The pixel component according to claim 1, wherein each of the plurality of pixels corresponds to a predetermined color, and is divided into each of the sub-pixels among the plurality of pixel components. Is a color filter for a liquid crystal device formed by being divided into each of the sub-pixels. 7. The number of pixels according to claim 5, wherein the plurality of pixels have different sizes between at least two colors.
An electro-optical device, wherein the number of divisions of the pixel into the sub-pixels is different between at least the two colors.   An electronic apparatus comprising the electro-optical device defined in any one of claims 1 to 7. An electro-optic device having a droplet ejection step of ejecting droplets from a nozzle opening of an ejection head to form at least one pixel component in each of a large number of pixels configured in a matrix on an electro-optic device substrate In the manufacturing method,
Before performing the droplet discharge step, the pixel has a dividing step of dividing the pixel into a plurality of sub-pixels having a planar shape whose dimensional ratio in two orthogonal directions is closer to 1: 1 than the pixel;
In the droplet discharging step, a droplet is discharged from the nozzle opening to each of the plurality of sub-pixels.   10. The dividing step according to claim 9, wherein in the dividing step, a partition capable of preventing the liquid droplet from flowing out of the sub-pixel is formed around and within the pixel to divide the pixel into the plurality of sub-pixels. A method of manufacturing an electro-optical device.

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