JP2006059772A - Organic el device, its manufacturing method, printer head, lighting system and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device having an organic thin film formed by having uniform film thickness and film quality over a wide range on a substrate, and capable of uniformly and properly emitting light. <P>SOLUTION: This organic EL device is composed by forming a plurality of organic EL elements on a substrate. The organic EL device is characterized by that each organic EL element comprises a pair of electrodes and an organic functional layer sandwiched between both the electrodes; at least one layer of an organic thin film constituting the organic functional layer is partially formed on the substrate by straddling the plurality of organic EL elements; and the organic thin film is formed by selectively arranging a liquid material in a formation area on the substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL device and a manufacturing method thereof, a printer head, a lighting device, and an electronic apparatus.

  2. Description of the Related Art Conventionally, light emitting devices capable of planar light emission are known as light sources for displays, illumination light sources, electrophotographic copying machines, optical communication processing devices, and the like. In this type of planar light source, an inorganic EL (electroluminescence) element is generally used. However, since an inorganic EL element requires a high-voltage AC power source for driving, an organic EL element that can be driven at a low voltage is used. Development of the planar light source used is in progress.

The organic EL element has a thin film made of an organic functional material as a layer that contributes to light emission, and the film thickness is usually 100 nm or less. As a method for forming such an organic thin film, vapor deposition is generally used in the case of a low molecular organic functional material, but it is difficult to form a film uniformly over a large area by the vapor deposition method. It has been studied to form an organic thin film having a uniform film thickness over a large area by applying a polymer material to the substrate using a liquid phase method. When forming the organic thin film described above by the liquid phase method, for example, Patent Document 1 describes using a spin coating method, and Patent Document 2 describes attaching a liquid material on a substrate in the form of microdroplets. The use of an inkjet method is described.
Japanese Patent Laid-Open No. 10-92576 JP 2002-252083 A

However, when an organic thin film is formed by spin coating, a part of the liquid material supplied onto the substrate is removed by flying to the outside of the substrate, so that the use efficiency of the material is low and the film formation cost increases. is there. In the spin coating method, since a liquid material is applied to the entire surface of the substrate, a step of removing the thin film after film formation is necessary for a region where the thin film is unnecessary.
On the other hand, the ink jet method is extremely effective for applications in which a liquid material is selectively disposed in a fine region using a partition that separates elements, and the liquid material can be disposed on a substrate in a desired planar shape. . However, when the ink jet method is used for the purpose of forming a monochromatic element in a large area such as a flat light source, there is a problem that the film thickness is likely to be uneven due to the landing accuracy of the liquid droplets.

The present invention has been made in view of the above-mentioned problems of the prior art, and has an organic thin film formed with a uniform film thickness and film quality over a wide range on a substrate. An object of the present invention is to provide an organic EL device capable of emitting light.
Further, the present invention is capable of forming an organic thin film having a uniform film thickness and film quality over a wide range on a substrate, and preferably has a good function of a constituent member provided in a non-formation region of the organic thin film. An object of the present invention is to provide a method for manufacturing an organic EL device that can be used.

In order to solve the above-described problems, the present invention provides an organic EL device in which an organic EL element including a pair of electrodes facing each other with an organic functional layer interposed therebetween is formed on a substrate, the organic functional layer The organic EL device is characterized in that at least one layer of the organic thin film forming the liquid crystal is formed by planarly applying a liquid material to a formation region on the base of the organic thin film. .
In the organic EL device having such a configuration, the organic thin film constituting the organic EL element is formed by applying a liquid material to a predetermined area on a substrate in a plane. That is, the liquid material for forming the organic thin film in the manufacturing process is formed without being disposed in the region where the organic thin film is not formed. By adopting such a configuration, it is possible to prevent the waste of the liquid material as in the case of using the spin coating method, thereby improving the use efficiency of the material and obtaining an organic EL device that can be manufactured at a low cost. it can. Further, by applying the liquid material on a flat surface, the liquid layer thickness of the liquid material formed on the substrate becomes uniform, and therefore, an organic thin film having a uniform film thickness and film quality in the surface direction can be formed. An organic EL device that is uniform and can emit light with high efficiency can be obtained.

The present invention is also an organic EL device in which a plurality of organic EL elements are formed on a substrate, wherein the organic EL element includes a pair of electrodes and an organic functional layer sandwiched between the electrodes. And at least one layer of the organic thin film constituting the organic functional layer is partially formed on the substrate across the plurality of organic EL elements, and the organic thin film is formed only in a formation region on the substrate. The organic EL device is characterized by being formed by arranging a liquid material in a plane.
In the organic EL device having such a configuration, in the configuration in which a plurality of organic EL elements are disposed on the substrate, one or more organic thin films constituting the organic functional layer are formed across the plurality of organic EL elements, and In this way, a plurality of organic thin films are formed by applying a liquid material on a plane only in the formation region. According to this configuration, like the organic EL device described above, an organic EL device that can be manufactured at low cost because it can be used with high efficiency, and that has excellent film thickness and film quality uniformity is provided. can do.

In the organic EL device of the present invention, the organic functional layer of the organic EL element may include an organic thin film patterned using a liquid material containing an aqueous solvent. It is preferable that the liquid material containing the aqueous solvent is obtained by dissolving an organic functional material containing 3,4-polyethylenedioxythiophene (PEDOT) in water.
When the organic thin film formed using the liquid material containing the aqueous solvent is included in the organic thin film constituting the organic functional layer in this way, when forming a plurality of layers included in the organic functional layer by the liquid phase method It becomes easy to prevent phase dissolution of the organic functional layer. In addition, among organic thin films constituting the organic functional layer, organic thin films formed using a liquid material containing an aqueous solvent are removed even if they are patterned after being formed on the entire surface of the substrate. Since it is difficult for residues to remain in the region, the liquid material may not be formed by applying the liquid material on the surface only in the formation region. In other words, in the present invention, among the organic thin films constituting the organic functional layer, the organic thin film formed using a liquid material containing a non-aqueous solvent is applied by applying a liquid material to only the formation region. It is preferable to form it.

  In the organic EL device of the present invention, the organic thin film constituting the organic functional layer may be a laminated film of two or more layers, and the organic thin film formed over a plurality of organic EL elements is two layers. It can also be set as the structure which is the above laminated film.

  In the organic EL device of the present invention, a terminal portion electrically connected to the organic EL element may be provided in a non-formation region of the organic thin film. In the present invention, since the organic thin film is formed by applying a liquid material on only the formation region, the non-formation region of the organic thin film is a portion where the liquid material of the organic thin film is not in contact. If the terminal part is formed in a region where there is no history of the liquid material or part of the organic thin film adhering in this way, the organic thin film residue adheres to the terminal part or the laser used for removing the organic thin film The terminal portion is not damaged by light or the like, and an organic EL device having a terminal portion with excellent electrical and physical reliability can be obtained.

  In the organic EL device of the present invention, the terminal portion may be an external connection terminal of the organic EL device or an electrode terminal connected to an electrode of the organic EL element.

  In the organic EL device of the present invention, it is preferable that the light emission of the plurality of organic EL elements is a single color. If the light emission colors of a plurality of EL elements are single, the liquid materials constituting the organic functional layer are naturally the same, and these can be uniformly applied over a wide area. In addition, the light emission luminance can be made uniform.

The manufacturing method of the organic EL device of the present invention is a manufacturing method of an organic EL device in which an organic EL element is formed on a substrate, and the organic EL device is electrically connected to the organic EL device on the substrate. A step of forming a terminal portion to be connected to the organic EL device, and when forming the organic EL device, a liquid material is applied in a planar manner to a region on the substrate excluding the terminal portion, thereby forming the organic EL device. The organic thin film which comprises is formed.
According to this manufacturing method, the organic thin film contained in the organic EL element can be formed in a lump by flat coating, and the material is not wasted as in the spin coating method, so that the use efficiency of the material can be improved. An organic EL device can be manufactured at low cost. Also, since the liquid material of the organic thin film is applied to the area excluding the terminal part formed on the substrate, the terminal part and the liquid material do not come into contact with each other, and the electrical reliability of the terminal part is maintained well. can do.

The manufacturing method of the organic EL device of the present invention is a manufacturing method of an organic EL device in which a plurality of organic EL elements are formed on a base, and one electrode constituting the organic EL element is formed on the base. A step of forming a plurality of electrodes, and a step of forming an organic thin film constituting the organic EL element by planarly applying a liquid material to a region on a substrate straddling a region where the plurality of electrodes are formed. And
According to this manufacturing method, the same effect as described above can be obtained in manufacturing an organic EL device including a plurality of organic EL elements.

  In the method for producing an organic EL device of the present invention, it is preferable to use a slit coating method, a roll coating method, or a printing method when a liquid material is selectively disposed on the substrate. By using these coating methods, it becomes possible to easily and highly accurately apply a liquid material to a selected region.

In the method for manufacturing an organic EL device of the present invention, it is preferable that the liquid material has a viscosity of 5 cP or less and a solute concentration of 1 wt% or less.
In the method for producing an organic EL device of the present invention, the liquid material preferably has a viscosity of 2 cP or less.
In the method for producing an organic EL device of the present invention, the solute concentration of the liquid material is more preferably 0.1% by weight or less.
By setting the viscosity and concentration within the above ranges, it is possible to obtain a liquid material that can be applied on the substrate with a uniform liquid layer thickness, and to easily form an organic thin film having a uniform film quality and thickness on the substrate. become.

  In the method for producing an organic EL device of the present invention, the liquid material can be applied onto the substrate while heating. In order to achieve good wetting and spreading of the liquid material on the substrate and to obtain a uniform liquid layer thickness, it is preferable that the viscosity of the liquid material is low, but there are cases where the viscosity cannot be lowered due to restrictions depending on the type of material. Therefore, if the liquid material is applied while being heated as in this manufacturing method, the viscosity of the liquid material can be reduced, and the liquid material can be satisfactorily wetted and spread on the substrate.

The printer head of the present invention is characterized by including the organic EL device of the present invention described above. According to the present invention, it is possible to provide a printer head excellent in uniformity of luminance of a single color.
The illumination device of the present invention includes the organic EL device of the present invention described above. ADVANTAGE OF THE INVENTION According to this invention, the illuminating device excellent in the uniformity of the brightness | luminance of white or a single color can be provided.

  A display device according to the present invention includes the above-described illumination device according to the present invention. According to this configuration, it is possible to provide a display device that includes the illumination device capable of obtaining uniform surface light emission and has excellent display luminance uniformity.

An electronic apparatus according to the present invention includes the printer head according to the present invention.
An electronic apparatus according to the present invention includes the illumination device according to the present invention.
An electronic apparatus according to the present invention includes the display device according to the present invention.
An electronic apparatus according to the present invention includes the organic EL device described above.

(Method for manufacturing organic EL device)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional configuration diagram showing a basic configuration of an organic EL device according to the present invention, and FIGS. 2 to 4 are cross-sectional views of main parts of a coating apparatus applicable to the manufacturing method according to the present embodiment. Shows an example constituted by a die coater, and FIGS. 3 and 4 show examples constituted by a flexographic printing apparatus.

An organic EL device 10 according to this embodiment shown in FIG. 1 has a configuration in which an organic EL element 19 is disposed on a substrate (base body) 11, and the organic EL element 19 has an anode on one surface side of the substrate 11. (First electrode) 12, an organic EL layer (organic functional layer) 13, and a cathode (second electrode) 14 are sequentially laminated. The organic EL layer 13 has a configuration in which a hole injection layer 15, a hole transport layer 16, a light emitting layer 17, and an electron transport layer 18 are stacked in this order from the anode 12 side.
The organic EL device 10 of the present embodiment can be applied to either an active matrix type or a passive matrix type as its driving method, and by supplying current to the organic EL layer 13 through the electrodes 12 and 14, the light emitting layer 17 is caused to emit light, and light can be emitted to the outer surface side of the substrate 11.

For example, the organic EL device 10 of the present embodiment can be configured to extract output light from the light emitting layer 17 from the substrate 11 side. In this case, the substrate 11 is made of a transparent or translucent material capable of transmitting light. A transparent or translucent anode 12 capable of transmitting light is formed on the substrate 11. Although not shown in the present embodiment, elements such as wirings and thin film transistors can be formed on the substrate 11.
Examples of the transparent or translucent material that can transmit light as the constituent material of the substrate 11 include transparent glass, quartz, sapphire, or transparent synthetic resin such as polyester, polyacrylate, polycarbonate, and polyetherketone. Is mentioned. In particular, as a material for forming the substrate 11, inexpensive soda glass is preferably used. The anode 12 is a transparent electrode made of indium tin oxide (ITO) or the like.

  On the other hand, in the case where light is extracted from the cathode 14 side opposite to the substrate 11, the material constituting the substrate 11 may be opaque, and in this case, the surface is placed on a ceramic sheet such as alumina or a metal sheet such as stainless steel. An insulating treatment such as oxidation, a thermosetting resin, a thermoplastic resin, or the like can be used. In this case, the anode 12 can also be formed of a light shielding or light reflecting material.

  The hole injection layer 15 has a function of increasing a hole injection rate from the anode 12 to the organic EL layer 13, and provides a function of improving element characteristics such as light emission efficiency and lifetime in the organic EL layer. As a material (formation material) for forming the hole injection / transport layer, for example, a thiophene compound (polythiophene (PEDOT) or the like), a pyrrole compound (polypyrrole or the like), an aniline compound (polyaniline or the like), an acetylene type, for example. A compound (such as polyacetylene) or a derivative thereof can be used.

Further, in this embodiment, a hole transport layer 16 is further provided on the hole injection layer 15, and charges injected through the hole injection layer 15 are transported to the light emitting layer 17 with high efficiency, and light emission is performed. The electrons moving in the layer 17 are blocked. The hole transport layer 16 is provided as necessary.
As the hole transport layer 16, for example, various organic materials classified into amine, hydrazone, stilbene, and starbust are known. For example, a triphenylamine derivative (TPD), a pyrazoline derivative, an arylamine derivative, a stilbene derivative, a triphenyldiamine derivative, or the like can be used.

As a material for forming the light emitting layer 17, low molecular organic light emitting dyes and polymer light emitters, that is, organic electroluminescent materials having light emitting properties such as various fluorescent materials and phosphorescent materials can be used.
Polymer light-emitting substances include conjugated polymers such as polyaryl vinylenes and polyfluorenes, coumarins, perylenes, pyrans, anthrones, porphyrenes, quinacridones, N, N'-dialkyl-substituted quinacridones , Naphthalimide-based, N, N′-diaryl-substituted pyrrolopyrrole-based fluorescent dyes dissolved in a polymer such as polystyrene, polymethyl methacrylate, and polyvinyl carbazole can be used. In addition, these polymeric fluorescent substances dissolve polymeric light-emitting substances in single or mixed solvents such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, and water. Thus, a liquid material for forming a light emitting layer can be obtained. In addition, an antioxidant, a surfactant, a viscosity modifier and the like can be added to the liquid material.

  Examples of the material for forming the electron transport layer 18 include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorenone Examples include derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, and the like. Specifically, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum and the like are suitable. It can be illustrated as

  The cathode 14 is a metal electrode made of aluminum (Al), magnesium (Mg), gold (Au), silver (Ag), or the like. The cathode 14 may have a laminated structure in which a layer made of a metal halide or oxide is provided on the electron transport layer 18 side. As the metal, a metal element such as an alkali metal, an alkaline earth metal, a rare earth metal, or a transition metal can be used. The metal halide is preferably a metal fluoride, but may be other metal chlorides or metal bromides. And it is desirable to use lithium fluoride (LiF) as a specific metal halide. In addition to inorganic lithium compounds such as lithium fluoride, organic lithium compounds such as lithium benzoate and lithium acetate can also be employed.

  In the actual organic EL device 10, it is preferable to provide a sealing member that covers the cathode 14, and further, between the anode 12 and the substrate 11, the anode 12, the cathode 14, the organic EL layer 13, and the like from the substrate 12 side. It is preferable to provide a sealing layer for blocking air from entering. The sealing layer provided on the light extraction side is formed of a transparent material such as ceramic, silicon nitride, silicon oxynitride, or silicon oxide. Among these, silicon oxynitride is preferable from the viewpoint of transparency and gas barrier properties. The thickness of the sealing layer is preferably smaller than the wavelength of light emitted from the light emitting layer 17 (for example, 0.1 μm).

  In the present invention, at least one layer of the organic EL layers 13 constituting the organic EL element 19 having the above-described configuration is formed by applying a liquid material to a partial region on the substrate 11. In applying the liquid material, the application apparatus shown in FIGS. 2 to 4 can be preferably used.

  A die coater (coating apparatus) 50 shown in FIG. 2 is mainly composed of a die 51 and a liquid material supply unit 52. The liquid material supply unit 52 may include, for example, a material container that stores the liquid material and a pump that conveys the liquid material from the material container to the die 51. In addition to these, the flow rate of the liquid material You may provide the valve | bulb which adjusts, and the buffer for hold | maintaining the supply pressure of liquid material uniformly. With such a configuration, the die coater 50 is disposed with the tip of the die 51 close to the substrate 11 and is provided from the liquid material supply unit 52 to the inside of the die 51 while moving the substrate 11 in the direction of the arrow in the figure. By supplying the liquid material to the nozzle portion 51a, a certain amount of the liquid material 13a can be applied onto the substrate 11. The liquid material 13a can be applied on the substrate 11 in a predetermined plane pattern by combining the transport operation of the substrate 11 and the supply / stop operation of the liquid material from the die 51.

A flexographic printing apparatus 60A shown in FIG. 3 is a so-called doctor roll type flexographic printing apparatus, and applies a liquid material to the printing plate roll 61 that supports the flexographic printing plate 61a on the peripheral surface and the flexographic printing plate 61a. An anilox roll 62 and a doctor roll 63 for applying a liquid material to the peripheral surface of the anilox roll 62 are provided.
In order to apply the liquid material to the substrate 11 by the flexographic printing apparatus 60A having the above-described configuration, first, the liquid material 13a is interposed between the doctor roll 63 and the anilox roll 62 while rotating the three rolls 61 to 63. Supply. Then, a small amount of the liquid material 13a is supplied to the peripheral surface of the anilox roll 62 from the gap between the doctor roll 63 and the anilox roll 62, and the liquid material 13a is applied from the anilox roll 62 to the flexographic printing plate 61a. When the substrate 11 is passed through a position close to the peripheral surface of the printing plate roll 61 in such an operating state, the liquid material 13a held on the surface of the flexographic printing plate 61a is transferred onto the substrate 11. According to this printing apparatus 60A, the liquid material 13a can be applied onto the substrate 11 in a planar pattern corresponding to the planar shape of the flexographic printing plate 61a.

  A flexographic printing apparatus 60B shown in FIG. 4 is a so-called doctor blade type flexographic printing apparatus, and includes a doctor blade 64 instead of the doctor roll 63 of the flexographic printing apparatus 60A shown in FIG. The flexographic printing apparatus 60B is similar to the flexographic printing apparatus 60A except that a doctor blade 64 having a tip portion disposed close to the peripheral surface of the anilox roll 62 is used when supplying the liquid material 13a to the peripheral surface of the anilox roll 62. Even when such a printing apparatus 60B is used, it is possible to apply the liquid material 13a on the substrate 11 in a predetermined plane pattern.

In the manufacturing method of the organic EL device according to the present embodiment, the liquid material 13a is applied on the substrate 11 in various plane patterns using the coating apparatus shown in FIGS. The organic thin film to be formed is formed on the substrate 11. The liquid material 13a used for coating on the substrate 11 by the coating apparatus shown in FIGS. 2 to 4 is, for example, when the hole injection layer 14 of the organic EL layer 13 is formed using a liquid phase method. , A liquid material in which a mixture of polythiophene derivatives such as polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) is dissolved in water. For example, when the blue light emitting layer 17 is formed, polydialkylfluorene and a derivative thereof, distyrylbiphenyl and a derivative thereof, tetraphenylbutadiene and a derivative thereof, and the like are used as a light emitting material. It is a liquid material prepared by dissolving in a solvent such as cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene.
As the light emitting material for forming the green light emitting layer 17, for example, polyparaphenylene vinylene and its derivatives, polyfluorene derivative F8BT or the like may be used instead of the blue light emitting material. In the case of forming, for example, a light emitting material such as a material obtained by adding a dye such as rhodamine to polyparaphenylene vinylene or a polyfluorene derivative may be used.

  In the present invention, the liquid material 13a to be applied to the substrate 11 has a viscosity of preferably 5 cP or less, and more preferably 2 cP or less. When the viscosity exceeds 5 cP, the supply from the nozzle 51 a shown in FIG. 2 or the supply of the liquid material to the anilox roll 62 may not be smoothly performed during application using the application apparatus shown in FIGS. is there. If the viscosity is 2 cP or less, coating by a coating apparatus can be performed very smoothly. Furthermore, in order to lower the viscosity of the liquid material 13a, the liquid material 13a may be applied while heating. For example, the liquid material 13a can be applied while heating the die 51 shown in FIG. 2 or the printing plate roll 61 or the anilox roll 62 shown in FIGS. In this case, the heating is performed so that the liquid material 13a does not change in quality, for example, about 20 to 80 ° C.

  The solute concentration in the liquid material 13a is preferably 1% by weight or less, and more preferably 0.1% by weight or less. The organic thin film constituting the organic EL layer 13 is a very thin film of about 10 to 100 nm. However, if the solute concentration exceeds 1% by weight, a local concentration distribution tends to occur during drying, and the organic thin film becomes uniform. It becomes difficult to form with film thickness and film quality.

FIG. 5 is a plan configuration diagram showing an example of an application form of the liquid material 13 a to the substrate 11. On the substrate 11 shown in FIG. 5A, an anode 12 constituting an organic EL element is formed in a rectangular shape in plan view, and a liquid material 13a is applied so as to cover the anode 12. Further, on the substrate 11, there are areas (non-application areas) 13x and 13y where the liquid material 13a is not applied, and these non-application areas are electrically connected to, for example, the cathode 14 of the organic EL element. And a terminal part for connecting the organic EL element and an external circuit, and the like. The liquid material 13a is not applied to the non-formation regions 13x and 13y where these terminal portions are arranged over the entire process of forming the organic EL device.
That is, in the manufacturing method of the organic EL device of the present embodiment, when forming the organic thin film constituting the organic EL layer 13, the liquid material 13a is applied to the substrate 11 by using the previous die coater 50 and the flexographic printing devices 60A and 60B. The liquid material 13a is not touched to the non-formation regions 13x and 13y on the substrate 11 by forming them in a lump or continuous with respect to the predetermined regions (regions excluding the non-formation regions 13x and 13y in FIG. 5A). An organic thin film is formed.

  Also, as shown in FIG. 5B, when a plurality of anodes 12 are arranged on the substrate 11 so as to form a plurality of organic EL elements, the liquid is collectively covered so as to cover the plurality of anodes 12. The material 13a is applied, and an organic thin film is formed so that the liquid material 13a does not touch the non-application areas 13x1 and 13x2 on both sides in the y direction of the application area.

  By forming the organic thin film in this way, the organic thin film can be formed quickly and uniformly while using the liquid material 13a with high efficiency. Furthermore, the properties and terminal portions of the formed organic thin film It is possible to obtain an organic EL device having excellent reliability.

Here, it demonstrates more concretely with reference to FIG.
FIG. 6A is a diagram showing an end cross-sectional shape of the organic thin film 13b formed by applying the liquid material 13a on the substrate 11 using the die coater 50 shown in FIG. In FIG. 6B, after the liquid material 13a described above is applied to the entire surface of the substrate 11 to form the organic thin film 13b, the organic thin film 13b is partially dissolved and removed by a solvent to pattern the organic thin film 13b. It is a figure which shows the edge part cross-sectional shape of the organic thin film 13b in a case. FIG. 6C shows the case where the organic thin film 13b is patterned by coating the entire surface of the liquid material 13a on the substrate 11 to form the organic thin film 13b and then partially removing the organic thin film 13b by laser irradiation. It is a figure which shows the edge part cross-sectional shape of the organic thin film 13b.

  As is clear from comparison between FIG. 6A and FIGS. 6B and 6C, the organic thin film 13b (FIG. 6A) formed by applying the manufacturing method according to the present embodiment Although a part of the end portion 13e that is raised is formed, the portion where the step with the surface of the substrate 11 is formed has a smooth cross-sectional shape. In addition, since the liquid material 13a is not applied on the substrate 11 adjacent to the organic thin film 13b, the surface of the substrate 11 on which the organic thin film 13b is not formed remains clean. Even when the terminal portion or the like is formed, the connection reliability is not impaired.

  On the other hand, in the organic thin film 13b patterned using the solvent shown in FIG. 6B, the film thickness at the end 13e becomes thinner toward the tip, and the change in the film thickness is also irregular. It has become a thing. Further, the organic thin film residue 13d that could not be removed by the solvent tends to remain on the substrate 11. If such a residue 13d is present, the connection reliability may be lowered when the terminal portion or the like is formed in the region, which may lead to a decrease in manufacturing yield. .

  Further, in the organic thin film 13b patterned by laser irradiation shown in FIG. 6C, the shape of the end 13e is more distorted than when patterned using a solvent, and the particles 13p scattered by the laser irradiation are organic. Since it may adhere on the thin film 13b, it may adversely affect the characteristics (charge transport efficiency and light emission efficiency) of the organic thin film 13b itself. Further, as shown in FIG. 6C, since a part of the substrate 11 may be removed by laser irradiation and the uneven portion 11d may be formed on the substrate surface, the previous terminal portion is formed on the substrate 11 in the same region. And the like are not preferable because the terminal portion itself may be damaged.

  As described above, in the manufacturing method of the present embodiment, when the organic EL element is formed on the substrate 11, the organic thin film liquid material 13 a constituting the organic EL layer 13 is used as the organic thin film in the region on the substrate 11. Since the organic thin film is formed by selectively applying only to the region to be formed, the organic thin film is formed on the entire surface of the substrate, and then the excess organic thin film is removed and discarded as in the case of patterning. The organic EL device can be manufactured using the material with high efficiency. In addition, since the liquid material is not applied in advance to the area on the substrate where the organic thin film is not finally formed, even if the terminal portion or the like is formed in the same area, the connection reliability thereof The organic EL device having a high yield and high reliability can be manufactured without damaging the device or damaging the terminal portion itself.

  In the present invention, since the liquid material is applied using a commercially available coating apparatus as shown in FIGS. 2 to 4, it is possible to apply the liquid material with good uniformity on a large area substrate. it can. And since the organic thin film of a uniform film thickness can be formed, it can also contribute to the luminous efficiency improvement of an organic EL element.

  In the above embodiment, the liquid material application form on the substrate 11 has been described with reference to the two types of FIGS. 5A and 5B. However, the application apparatus shown in FIGS. The planar pattern of the liquid material 13a is not limited as long as it can be formed. For example, the liquid material 13a can be applied in various patterns as shown in FIGS. FIG. 7A shows a case where the liquid material 13a is intermittently applied in the x direction shown in the figure, and the non-application areas 13y1 and 13y2 are formed between or outside them. (B) has shown the case where the liquid material 13a is apply | coated to the strip | belt shape extended in illustration x direction, and the non-application | coating area | region 13x is formed adjacent to the application | coating area | region. Further, (c) shows L-shaped non-application areas 13x1 and 13y1 formed along the two side edges of the substrate 11, and a non-formation area 13x2 arranged in a cross shape on the center side of the substrate 11. 13y2 is formed, and the liquid material 13a is applied to other regions.

(Printer head)
Next, a printer head that can suitably use the organic EL device 10 of the above embodiment and the manufacturing method thereof will be described with reference to FIGS.

  FIG. 8 is a diagram schematically showing a printer head to which the organic EL device according to the present invention is applied, in which (a) is a bottom view and (b) is a side view. The printer head 1 according to the present embodiment is used as an exposure unit of an image forming apparatus to be described later. As shown in FIG. 8A, a plurality of organic EL elements are formed on a long and thin element substrate 2. 3, a single color light emitting element array 3 a, a driving element group including a driving element 4 that drives the organic EL element 3, and a control circuit group 5 that controls driving of these driving elements 4 (driving element group). Are integrally formed.

  Moreover, as shown in FIG.8 (b), the sealing substrate 6 is stuck on the element substrate 2 by the transparent adhesive in the state which sealed the organic EL element 3 on the surface side. . Here, the printer head 1 according to the present embodiment is not a bottom emission type that emits light emitted from the organic EL element 3 from the element substrate 2 side, but a top emission type that emits light from the sealing substrate 6 side. ing. Therefore, as described later, the sealing substrate 6 is made of a transparent substrate such as glass. The printer head 1 according to the present embodiment includes a heat radiating plate 7 made of a metal such as aluminum on the back side of the element substrate 2. The heat radiating plate 7 prevents a decrease in luminous efficiency and life of the organic EL element 3 by suppressing an increase in the ambient temperature of the organic EL element 3.

  As shown in FIG. 8A, power source lines 8 and 9 are connected to the drive element 4 formed on the element substrate 2, and a power source (not shown) is connected via these power source lines 8 and 9. A voltage is applied to the drive element 4. In such a configuration, the light emitting operation of the organic EL element 3 is controlled by the drive element 4 controlled by the control circuit group 5. Further, a temperature measuring unit for measuring the temperature of the light emitting element array 3a or the vicinity thereof may be provided on the printer head 1.

  Here, the configuration of the organic EL element 3 and the driving element 4 in the printer head 1 will be described. FIG. 9 is a side cross-sectional view illustrating the main configuration of the printer head 1, and FIG. 10 is a bottom view illustrating the main configuration of the printer head 1. FIG. 9 shows two types of cross-sectional configurations ((a) and (b)) that can be employed in the printer head 1.

  As described above, the printer head 1 according to the present embodiment is a top emission type and has a configuration in which emitted light is extracted from the sealing substrate 6 side, which is the opposite side of the element substrate 2. Any of the substrates can be used. When an opaque substrate is used as the element substrate 2, for example, a thermosetting resin, a thermoplastic resin, or the like is used in addition to a ceramic sheet such as alumina or a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation. Can do. However, in this embodiment, since a transparent glass substrate is used as the sealing substrate 6, a glass substrate is also used as the element substrate 2 in order to prevent problems such as warpage due to a difference in thermal expansion coefficient.

As shown in FIG. 9A, a circuit portion 35 including a driving TFT 21 (driving element 4) connected to the pixel electrode 20 is formed on the element substrate 2, and the organic EL element 3 is formed thereon. Is provided. The organic EL element 3 has a configuration in which a hole injection layer 32 formed over a plurality of pixel electrodes 20 is stacked on the pixel electrode 20 functioning as an anode. That is, the element substrate 2 according to the present embodiment has a plurality of anodes (electrodes) arranged on the substrate and straddling the plurality of electrodes, similarly to the organic EL device shown in FIG. It has a form in which an organic thin film is formed.
Although only the hole injection layer 32 is illustrated in FIG. 9A, the light emitting layer and the cathode are actually stacked on the hole injection layer 32.

  Here, FIG. 10 shows a schematic diagram in which the organic EL element 3 and the driving TFT 21 (driving element 4) correspond to FIG. In FIG. 10, the power supply line 8 is connected to the source / drain electrode of the drive element 4, and the power supply line 9 is connected to the cathode 30 of the organic EL element 3. As shown in FIG. 10, the organic EL element 3 emits light by combining holes injected from the hole transport layer 32 and electrons from the cathode 30 in the light emitting layer sandwiched between them.

  The pixel electrode 20 functioning as an anode is usually formed of ITO (Indium Tin Oxide). In addition, particularly in the case of the top emission type, when it is desired to obtain high contrast, titanium, tungsten, titanium-tungsten alloy or the like is formed as a reflective layer, and ITO is laminated on the reflective layer as an interference layer. The pixel electrode 20 may be formed by a laminated structure including these reflective layers and interference layers.

  As a material for forming the hole injection layer 32, in particular, a dispersion of 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), that is, 3,4-polyethylenedioxy in polystyrene sulfonic acid as a dispersion medium. A dispersion in which thiophene is dispersed and further dispersed in water is preferably used. The material for forming the hole injection layer 32 is not limited to the above, and various materials can be used. For example, those obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as the above-described polystyrene sulfonic acid can be used.

  As a material for forming the light emitting layer formed on the hole injection layer 32, a known light emitting material capable of emitting fluorescence or phosphorescence is used as in the light emitting layer 17 according to the previous embodiment. In the printer head application as in this embodiment, a single color light emitting layer corresponding to the red light emission wavelength band is preferably used. Of course, a light emitting layer corresponding to the light emission wavelength band corresponding to green or blue is used. You may make it do. In short, the emission color may be adapted to the best sensitivity wavelength region of the photoreceptor of the image forming apparatus described later.

  Specific examples of the material for forming the light emitting layer include (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), and polyvinylcarbazole (PVK). Polysilanes such as polythiophene derivatives and polymethylphenylsilane (PMPS) are preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as.

  The cathode 30 formed so as to cover the light emitting layer is formed of a transparent conductive material, particularly in the case of this embodiment which is a top emission type. As the transparent conductive material, a structure in which a co-deposited film of bathocuproine and cesium is used and ITO is laminated to impart conductivity is preferably employed. Instead of the co-deposited film of bathocuproine and cesium, Ca may be formed to a thickness of about 5 nm. Further, the sealing substrate 6 shown in FIG. 8 (not shown in FIG. 9) is stuck on the cathode via a transparent adhesive layer.

Further, as described above, the circuit unit 35 is provided below the organic EL element 3. The circuit portion 35 is formed on the element substrate 2. That is, a base protective layer 36 mainly composed of SiO ₂ is formed on the surface of the element substrate 2 as a base, and a silicon layer 41 is formed thereon. A gate insulating layer 37 mainly composed of SiO ₂ and / or SiN is formed on the surface of the silicon layer 41. In the silicon layer 41, a region overlapping with the gate electrode 42 with the gate insulating layer 37 interposed therebetween is a channel region 41a. The gate electrode 42 is a part of a scanning line (not shown). On the other hand, a first interlayer insulating layer 38 mainly composed of SiO ₂ is formed on the surface of the gate insulating layer 37 covering the silicon layer 41 and forming the gate electrode 42.

  In the silicon layer 41, a source region 41S is provided on the source side of the channel region 41a, while a drain region 41D is provided on the drain side of the channel region 41a. Among these, the source region 41 </ b> S is connected to the source electrode 43 through a contact hole 43 a that is opened across the gate insulating layer 37 and the first interlayer insulating layer 38. The source electrode 43 is configured as a part of a power supply line (not shown). On the other hand, the drain region 41 </ b> D is connected to the drain electrode 44 made of the same layer as the source electrode 43 through a contact hole 44 a that opens between the gate insulating layer 37 and the first interlayer insulating layer 38.

  On the first interlayer insulating layer 38 on which the source electrode 43 and the drain electrode 44 are formed, for example, a second interlayer insulating layer 39 mainly composed of an acrylic resin component is formed. The second interlayer insulating layer 39 is formed of silicon nitride, silicon oxide, silicon oxynitride, heat-resistant insulating resin such as acrylic or polyimide, and the like. The driving TFT 21 (driving element 4) and the source electrode 43, the drain electrode 44, etc., and the pixel electrode 20 formed thereon are formed to prevent a short circuit.

  On the surface of the second interlayer insulating layer 39, the pixel electrode 20 made of ITO or the like is formed and connected to the drain electrode 44 through a contact hole 23a penetrating the second interlayer insulating layer 39. ing. That is, the pixel electrode 20 is connected to the drain region 41 </ b> D of the silicon layer 41 through the drain electrode 44.

  A hole injection layer 32 is formed in a region including the plurality of pixel electrodes 20 on the surface of the second interlayer insulating layer 39 on which the pixel electrodes 20 are formed. Here, FIG. 11 is a diagram corresponding to FIG. 8A and is a plan configuration diagram for explaining a formation region of the hole injection layer 32. As shown in FIG. 11, a plurality of TFTs 21 and organic EL elements 3 are arrayed on the element substrate 2, but the hole injection layer 32 is a part of the element substrate 2 as shown in the figure. It is formed in a band shape that covers Then, the hole injection layer 32 having a band shape in plan view is formed by applying the liquid material to the illustrated position all at once using the coating apparatus shown in FIGS. That is, also in the element substrate 2 according to the present embodiment, the region on the substrate other than the formation region of the hole injection layer 32 is a region that does not contact the liquid material for forming the hole injection layer. In the printer head of the embodiment, the power supply line 9 connected to the cathode and the terminal portion 29 connected to the power supply lines 8 and 9 are provided in the non-application area. As described above, in the printer head according to the present embodiment, the hole injection layer 32 can be formed using a material with high efficiency, and the power line 9 and the terminal portion 29 and the organic EL layer are formed. Therefore, the reliability of the power supply line and the terminal portion due to the organic thin film residue and the removing means such as a laser is not lowered or damaged. Therefore, according to the present invention, a highly reliable printer head can be provided at low cost.

In the above embodiment, the cross-sectional structure of the element substrate 2 has been described with reference to FIG. 9A. However, the cross-sectional structure of the element substrate 2 may be as shown in FIG. 9B. In the example shown in FIG. 9B, an inorganic bank 25 made of an inorganic insulating material such as SiO ₂ is provided on the second interlayer insulating layer 39 and the pixel electrode 20. The inorganic bank 25 has an opening 25a in a region overlapping the pixel electrode 20 in a plane, and a hole injection layer 32 formed so as to cover the inorganic bank 25 and the pixel electrode 20; Is brought into contact with the opening 25a, whereby the organic EL element 3 having a planar region corresponding to the opening 25a is formed. If the inorganic bank 25 is provided in this way, the planar area of the organic EL element 3 can be freely changed by the opening diameter of the opening 25a, and the element can be arranged in accordance with the resolution of the printer head. Become.

(Image forming device)
Next, an image forming apparatus provided with the printer head 1 of the present invention will be described. FIG. 12 is a diagram showing a configuration of an image forming apparatus which is an embodiment of the electronic apparatus according to the invention. An image forming apparatus 80 shown in FIG. 12 includes four photosensitive drums (image bearing members) having the same configuration corresponding to organic EL array printer heads 81K, 81C, 81M, and 81Y, which are examples of the printer head of the above-described embodiment. Body) are arranged in 82K, 82C, 82M, and 82Y exposure apparatuses, respectively, and are configured as a tandem system.

  The image forming apparatus 80 includes a driving roller 83, a driven roller 84, and a tension roller 85, and an intermediate transfer belt 86 is stretched around each of the rollers so as to be circulated in an arrow direction (counterclockwise direction) in FIG. Is. Photoconductors 82K, 82C, 82M, and 82Y are arranged at predetermined intervals with respect to the intermediate transfer belt 86. These photoreceptors 82K, 82C, 82M, and 82Y have a photosensitive layer as an image carrier on their outer peripheral surfaces.

  Here, K, C, M, and Y in the above symbols mean black, cyan, magenta, and yellow, respectively, and indicate that the photoconductors are for black, cyan, magenta, and yellow, respectively. The meanings of these symbols (K, C, M, Y) are the same for the other members. The photoreceptors 82K, 82C, 82M, and 82Y are driven to rotate in the arrow direction (clockwise) in FIG. 12 in synchronization with the driving of the intermediate transfer belt 86.

  Around each photosensitive member 82 (K, C, M, Y), charging means (corona charger) 87 (K) for uniformly charging the outer peripheral surface of the photosensitive member 82 (K, C, M, Y), respectively. , C, M, Y) and the outer peripheral surface uniformly charged by the charging means 87 (K, C, M, Y) are synchronized with the rotation of the photosensitive member 82 (K, C, M, Y). And an organic EL array printer head 81 (K, C, M, Y) of the present invention that sequentially performs line scanning.

  Further, a developing device 88 (K) that applies toner as a developer to the electrostatic latent image formed by the organic EL array printer head 81 (K, C, M, Y) to form a visible image (toner image). , C, M, Y) and a primary transfer roller 89 as transfer means for sequentially transferring the toner image developed by the developing device 88 (K, C, M, Y) to the intermediate transfer belt 86 as a primary transfer target. (K, C, M, Y) and a cleaning device 90 (K, C, Y) as a cleaning unit for removing toner remaining on the surface of the photosensitive member 82 (K, C, M, Y) after being transferred. M, Y).

  Each organic EL array printer head 81 (K, C, M, Y) is installed such that each array direction is along the bus line of the photosensitive drum 82 (K, C, M, Y). The emission energy peak wavelength of each organic EL array printer head 81 (K, C, M, Y) and the sensitivity peak wavelength of the photoconductor 82 (K, C, M, Y) are set to substantially coincide. ing. Each organic EL array printer head 81 (K, C, M, Y) is supported and attached to the image forming apparatus 80 by a support member.

  The developing device 88 (K, C, M, Y) uses, for example, a non-magnetic one-component toner as a developer. The one-component developer is transported to the developing roller by a supply roller, for example, and adhered to the developing roller surface. The film thickness of the developed developer is regulated by a regulating blade, and the developing roller is brought into contact with or pressed against the photoreceptor 82 (K, C, M, Y), thereby the photoreceptor 82 (K, C, M, Y). In accordance with the potential level, a developer is attached and developed as a toner image.

  The black, cyan, magenta, and yellow toner images formed by the four-color single-color toner image forming station are intermediated by the primary transfer bias applied to the primary transfer roller 89 (K, C, M, Y). Primary transfer is sequentially performed on the transfer belt 86. The toner images, which are sequentially superimposed on the intermediate transfer belt 86 and become full color, are secondarily transferred to the recording medium P such as paper by the secondary transfer roller 91 and further pass through the fixing roller pair 92 as a fixing unit. Then, the toner image is fixed on the recording medium P and then discharged onto a paper discharge tray 94 formed on the upper part of the apparatus by a pair of paper discharge rollers 93.

  In FIG. 12, reference numeral 95 is a paper feed cassette in which a large number of recording media P are stacked and held, 96 is a pickup roller for feeding the recording media P one by one from the paper feed cassette 95, and 97 is a secondary transfer. A pair of gate rollers for defining the supply timing of the recording medium P to the secondary transfer portion of the roller 91; a secondary transfer roller 91 as a secondary transfer means for forming a secondary transfer portion with the intermediate transfer belt 86; A cleaning blade 98 serves as a cleaning unit that removes toner remaining on the surface of the intermediate transfer belt 86 after the secondary transfer. As described above, since the image forming apparatus of FIG. 12 uses the organic EL array printer head 81 (K, C, M, Y) as the exposure means (writing means), for example, when a laser scanning optical system is used. In comparison, the size of the apparatus can be reduced.

  Next, an image forming apparatus according to another embodiment of the present invention will be described. FIG. 13 is a longitudinal side view showing another embodiment of the image forming apparatus. In FIG. 13, the image forming apparatus 100 is provided with a rotary developing device 101, a photosensitive drum 105 functioning as an image carrier, and the printer head (organic EL array head) as main components. Means (exposure means) 107, intermediate transfer belt 109, paper conveyance path 114, fixing unit heating roller 112, and paper feed tray 118 are provided.

  The developing device 101 is configured such that the developing rotary 101a rotates in the direction of arrow A about a shaft 101b. The interior of the development rotary 101a is divided into four, and image forming units for four colors of yellow (Y), cyan (C), magenta (M), and black (K) are provided. Reference numerals 102a to 102d are arranged in the image forming units for the four colors, and developing rollers that rotate in the direction of arrow B, and 103a to 103d are toner supply rollers that rotate in the direction of arrow C. 104a to 104d are regulating blades that regulate the toner to a predetermined thickness.

  In FIG. 13, reference numeral 105 denotes a photosensitive drum that functions as an image carrier as described above, 106 denotes a primary transfer member, and 108 denotes a charger. Reference numeral 107 denotes an image writing means as an exposure means in the present invention, which comprises the organic EL printer head of the present invention. The photosensitive drum 105 is rotationally driven in the direction of arrow D, which is the opposite direction to the developing roller 102a, by a drive motor (not shown), for example, a step motor. The organic EL printer head constituting the image writing means 107 is disposed in a state where the alignment (optical axis alignment) is performed between this and the imaging lens (not shown) and the photosensitive drum 105. Yes.

  The intermediate transfer belt 109 is stretched between the driving roller 110a and the driven roller 110b. The drive roller 110 a is connected to the drive motor of the photosensitive drum 105 and transmits power to the intermediate transfer belt 109. That is, by driving the drive motor, the drive roller 110a of the intermediate transfer belt 109 is rotated in the direction of arrow E, which is the opposite direction to the photosensitive drum 105.

  The paper transport path 114 is provided with a plurality of transport rollers, paper discharge roller pairs 116, and the like, so that the paper is transported. An image (toner image) on one side carried on the intermediate transfer belt 109 is transferred to one side of the paper at the position of the secondary transfer roller 111. The secondary transfer roller 111 is brought into contact with and separated from the intermediate transfer belt 109 by a clutch. When the clutch is turned on, the secondary transfer roller 111 is brought into contact with the intermediate transfer belt 109 so that an image is transferred onto a sheet.

  The sheet on which the image has been transferred as described above is then subjected to a fixing process by a fixing device having a fixing heater H. The fixing device is provided with a heating roller 112 and a pressure roller 113. The sheet after the fixing process is drawn into the discharge roller pair 116 and proceeds in the direction of arrow F. When the paper discharge roller pair 116 rotates in the opposite direction from this state, the paper reverses its direction and advances on the duplex printing conveyance path 115 in the direction of arrow G. 117 is an electrical component box, 118 is a paper feed tray for storing paper, and 119 is a pickup roller provided at the outlet of the paper feed tray 118.

  For example, a low-speed brushless motor is used as a drive motor for driving the transport roller in the paper transport path. Further, a step motor is used for the intermediate transfer belt 109 because color misregistration correction or the like is necessary. Each of these motors is controlled by a signal from a control means (not shown).

  In the state shown in FIG. 13, a yellow (Y) electrostatic latent image is formed on the photosensitive drum 105, and a high voltage is applied to the developing roller 102a, whereby a yellow image is formed on the photosensitive drum 105. Is done. When all of the yellow back side and front side images are carried on the intermediate transfer belt 109, the development rotary 101a rotates 90 degrees in the direction of arrow A.

  The intermediate transfer belt 109 rotates once and returns to the position of the photosensitive drum 105. Next, two images of cyan (C) are formed on the photosensitive drum 105, and this image is carried on the yellow image carried on the intermediate transfer belt 109. Thereafter, the 90-degree rotation of the development rotary 101 and the one-rotation process after the image is carried on the intermediate transfer belt 109 are repeated in the same manner.

  For carrying four color images, the intermediate transfer belt 109 rotates four times, and then the rotation position is further controlled to transfer the image onto the sheet at the position of the secondary transfer roller 111. The paper fed from the paper feed tray 118 is transported by the transport path 114, and the above color image is transferred to one side of the paper at the position of the secondary transfer roller 111. The sheet on which the image is transferred on one side is reversed by the pair of discharge rollers 116 as described above, and waits on the conveyance path. Thereafter, the sheet is conveyed to the position of the secondary transfer roller 111 at an appropriate timing, and the above color image is transferred to the other side. The housing 120 is provided with an exhaust fan 121.

  As described above, the image forming apparatus including the organic EL printer head has been described as an embodiment of the electronic apparatus of the present invention. However, the image forming apparatus including the printer head of the present invention is not limited to the above-described embodiment, and various Can be modified.

(Lighting device)
In the above embodiment, the form in which the organic EL device according to the present invention is applied to a printer head has been described. However, the organic EL device according to the present invention is a surface light emitting device such as a white light source, indoor lighting, and a backlight light source for a liquid crystal display. It can also be configured as a mold illumination device. Hereinafter, the form as an illuminating device is demonstrated, referring FIG. Note that the cross-sectional structure of the liquid crystal device shown in FIG. 14 is shown by changing the thickness of each layer to a thickness different from that of an actual liquid crystal device so that each layer can be easily seen in the drawing.

  FIG. 14 is a cross-sectional view showing an example of the configuration of the liquid crystal display device according to the present invention. A liquid crystal device 200 according to the embodiment shown in FIG. 14 includes a pair of substrates 213 and 214 arranged to face each other, and a liquid crystal layer 215 sandwiched between these substrates and sealed by an annular sealing material 212. The liquid crystal panel 211 is configured to include the prism sheet 222 disposed on the back surface side (the lower surface side in the drawing), and the backlight (illuminating device) 230.

  The substrate 213 arranged on the front side (the upper side in the figure) is provided with a retardation plate 219 and a polarizing plate 216 on the outer side (the upper side in the figure) of a translucent substrate body 217 made of a transparent material such as glass. In addition, a color filter layer 224, an overcoat layer 221 and an electrode layer 223 made of a transparent conductive film having a stripe shape in plan view are formed on the inner surface side (the liquid crystal layer 215 side). In the present embodiment, each of the electrode layers 223 is formed by patterning a transparent conductive film made of ITO (Indium Tin Oxide) or the like in a stripe shape in plan view, and matches the display area of the liquid crystal panel 211 and the number of pixels. The required number is formed.

  In the actual liquid crystal device, alignment films are formed on the liquid crystal layer 215 side of the electrode layer 223 and on the liquid crystal layer 215 side of the striped electrode layer 235 on the lower substrate side described later. Illustration of these alignment films is omitted. The liquid crystal layer 215 is made of, for example, a TN liquid crystal whose orientation is controlled at a predetermined twist angle.

  The color filter layer 224 is formed by partitioning each RGB pattern for color display by a black matrix (not shown) serving as a light-shielding means. On the color filter layer 224, the RGB pattern is protected, An overcoat layer 221 is coated as a transparent protective flattening film for flattening the unevenness caused by the RGB pattern. As the black matrix, for example, a pattern obtained by patterning a metal thin film of chromium or the like having a thickness of about 100 to 200 nm by a sputtering method, a vacuum deposition method or the like can be used. In the above RGB pattern, a red pattern (R), a green pattern (G), and a blue pattern (B) are arranged in a desired pattern shape. For example, pigment dispersion using a photosensitive resin containing a predetermined colorant And various printing methods, electrodeposition methods, transfer methods, dyeing methods, and the like.

  On the other hand, the substrate 214 disposed on the back side is provided with a transflective layer 231, an overcoat layer 233 on the inner surface side (liquid crystal layer 215 side) of the light-transmitting substrate body 228 made of a transparent material such as glass, An electrode layer 235 made of a transparent conductive film having a stripe shape in plan view is sequentially formed, and a retardation plate 26 and a polarizing plate 27 are provided on the outer surface side (lower surface side in the drawing) of the substrate body 228. ing. The electrode layer 235 is arranged to extend in a direction intersecting with the electrodes of the electrode layer 223 facing each other with the liquid crystal layer 215 interposed therebetween.

  The prism sheet 222 is provided with a prism surface 222a on one surface side of a flat plate material made of a transparent acrylic resin or the like, and the prism surface 222a is formed by forming periodic irregularities having a triangular wave cross section. ing. In the liquid crystal device 200 of the present embodiment, two prism sheets 222 having such a shape are arranged so as to overlap each other, and the extending directions of the ridges formed on the prism surfaces of both prism sheets are orthogonal to each other. Are arranged as follows. By providing these prism sheets 222, illumination light from the backlight 230 can be efficiently incident on the liquid crystal panel 211.

  As shown in FIG. 14, the backlight 230 has an anode 242, a hole injection layer 243, a light emitting layer 244, and a cathode 245 formed in this order on the outer surface side (lower surface side in the drawing) of the translucent substrate 241. The organic EL element 250 is provided. The light generated in the light emitting layer 244 according to the amount of current flowing through the organic EL element 250 is extracted from the substrate 241 side and output as illumination light.

As the constituent material of the hole injection layer 243 and the light emitting layer 244, the same material as the constituent material of the hole injection layer 15 and the light emitting layer 17 shown in FIG. 1 can be used. In addition, as in the previous embodiment, it is needless to say that a hole transport layer or an electron transport layer can be provided as necessary.
When configured as a lighting device as in this embodiment, it is preferable to use a material made of a material capable of obtaining white light emission for the light emitting layer 244. White is not strictly composed of a single color, but is defined as a single color in the present invention.
The cathode 245 is preferably formed of a metal material having light reflectivity such as aluminum, silver, or a silver alloy so as to reflect light emitted from the light emitting layer 244 and emit the light toward the substrate 241 side.

  In the liquid crystal device 200 having the above configuration, the backlight 230 includes the organic EL device according to the present invention. That is, the hole injection layer 243 and the light emitting layer 244 constituting the organic EL element 250 were formed by selectively applying a liquid material on the substrate 241 using the application apparatus shown in FIGS. It consists of an organic thin film. Therefore, since the hole injection layer 243 and the light emitting layer 244 according to the present embodiment are formed by batch application using a liquid phase method, the film thickness and the film quality are excellent in uniformity, and the light emission efficiency is high. It is also high in brightness uniformity and monochromaticity.

  In addition, since a necessary amount of liquid material is applied on the substrate 241, the backlight 230 can be manufactured at low cost by increasing the material use efficiency when forming the organic EL element 250. Furthermore, since the liquid material is disposed only in a predetermined region (light emitting region) on the substrate 241 when applying the liquid material using the coating apparatus, for example, a connection terminal for an external circuit such as a drive circuit outside the light emitting region. Etc., the connection terminal and the liquid material do not come into contact with each other, and the reliability of the connection terminal is hardly lowered. Therefore, the backlight 230 of the present embodiment is excellent in electrical reliability such as external connection terminals.

  Since the liquid crystal device of the present embodiment is a transflective type, the backlight 230 is not always lit, but only when there is little ambient light (external light), and is lit by a user or sensor instruction. Can be. That is, when sufficient ambient light is obtained, the backlight is turned off and the liquid crystal panel 211 is operated as a reflective liquid crystal panel. In such a transflective liquid crystal panel 211, a layer called a transflective layer 231 is formed. The transflective layer 231 has a reflective layer made of Ag or Al in the pixel region. For example, it can be formed on a substrate body 228 shown in FIG. 14 by vapor deposition or sputtering. The transflective layer 231 may be formed of a reflective layer having a thickness capable of partially transmitting light emitted from the backlight 230 provided below the liquid crystal panel 211. What is widely used for liquid crystal type liquid crystal devices can be appropriately employed. Further, when the transflective layer is made of a material having both light reflectivity and conductivity, the transflective layer can also serve as a driving electrode.

  In the liquid crystal device of the present embodiment, the case where the simple matrix type transflective liquid crystal panel is provided with the illumination device has been described. However, the liquid crystal panel is not provided with a two-terminal switching element or a three-terminal switching element. Needless to say, the active matrix transflective liquid crystal panel may be provided.

(Electronics)
FIG. 15 is a perspective configuration diagram illustrating a mobile phone that is an electronic device including the liquid crystal device according to the embodiment in a display unit. A cellular phone 1300 is mainly configured by a display unit 1301, an operation unit 1302, a reception unit 1303, and a transmission unit 1304, and the display unit 1301 includes the liquid crystal device according to the embodiment. This mobile phone is a mobile phone which can obtain a bright display on the liquid crystal display unit equipped with the lighting device according to the present invention and is excellent in the reliability of the display unit.

It is a section lineblock diagram of an organic EL device concerning an embodiment. The cross-sectional block diagram which shows the film-forming process by a slit coater. Sectional process drawing which shows the film-forming process using the flexographic printing apparatus. Sectional process drawing which shows the film-forming process using the flexographic printing apparatus. The plane block diagram which shows the film-forming form by the manufacturing method which concerns on embodiment. The cross-sectional block diagram for demonstrating the edge part shape of an organic thin film equally. The plane block diagram which shows the film-forming form by the manufacturing method which concerns on embodiment. FIG. 3 is a diagram illustrating a planar configuration and a side configuration of the printer head according to the embodiment. The figure which shows a partial cross section structure similarly. The figure which shows the planar structure of an organic EL element. The plane block diagram for demonstrating the formation area of a positive hole injection layer similarly. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment. The figure which shows the structure of the liquid crystal device (illumination device) which concerns on embodiment. FIG. 11 is a perspective configuration diagram illustrating an example of an electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer head, 2 element board | substrate (base | substrate), 3 organic EL element, 10 organic EL apparatus, 11 board | substrate (base | substrate), 12 anode, 13 organic EL layer, 14 cathode, 15 hole injection layer, 16 hole transport layer, 17 light emitting layer, 18 electron transport layer, 19 organic EL element, 29 terminal, 200 liquid crystal device, 230 backlight (illumination device; organic EL device)

Claims (17)

An organic EL device in which an organic EL element including a pair of electrodes facing each other with an organic functional layer interposed therebetween is formed on a substrate,
An organic EL device characterized in that at least one layer of the organic thin film forming the organic functional layer is formed by planarly applying a liquid material only to a formation region on the base of the organic thin film. . An organic EL device in which a plurality of organic EL elements are formed on a substrate,
The organic EL element includes a pair of electrodes and an organic functional layer sandwiched between the electrodes,
At least one layer of the organic thin film constituting the organic functional layer is partially formed on the substrate across the plurality of organic EL elements,
An organic EL device, wherein the organic thin film is formed by applying a liquid material in a planar manner only to a formation region on the substrate.   The organic EL device according to claim 1, wherein the organic functional layer of the organic EL element includes an organic thin film patterned using a liquid material containing an aqueous solvent.   The organic EL device according to claim 3, wherein the liquid material containing the aqueous solvent is obtained by dissolving an organic functional material containing 3,4-polyethylenedioxythiophene (PEDOT) in water.   5. The organic EL device according to claim 1, wherein a terminal portion electrically connected to the organic EL element is provided in a non-formation region of the organic thin film.   The organic EL device according to claim 5, wherein the terminal portion is an external connection terminal of the organic EL device or an electrode terminal connected to an electrode of the organic EL element.   7. The organic EL device according to claim 1, wherein light emission of the plurality of organic EL elements is a single color. A method for producing an organic EL device comprising an organic EL element formed on a substrate,
Forming the organic EL element and a terminal portion electrically connected to the organic EL element on the substrate;
When forming the organic EL element, an organic thin film constituting the organic EL element is formed by planarly applying a liquid material to a region on the substrate excluding the terminal portion. Device manufacturing method. A method for producing an organic EL device comprising a plurality of organic EL elements formed on a substrate,
Forming a plurality of electrodes on one side constituting the organic EL element on the substrate;
Forming an organic thin film that constitutes the organic EL element by planarly applying a liquid material to a region on a substrate straddling a region where the plurality of electrodes are formed;
The manufacturing method of the organic electroluminescent apparatus characterized by the above-mentioned.   The method for manufacturing an organic EL device according to claim 8 or 9, wherein a slit coating method, a roll coating method, or a printing method is used when the liquid material is selectively disposed on the substrate.   11. The method of manufacturing an organic EL device according to claim 8, wherein a viscosity of the liquid material is 5 cP or less and a solute concentration thereof is 1 wt% or less.   12. The method of manufacturing an organic EL device according to claim 11, wherein the liquid material has a viscosity of 2 cP or less.   13. The method of manufacturing an organic EL device according to claim 11, wherein a solute concentration of the liquid material is 0.1 wt% or less.   14. The method of manufacturing an organic EL device according to claim 8, wherein the liquid material is applied onto the substrate while being heated.   A printer head comprising the organic EL device according to claim 1.   An illuminating device comprising the organic EL device according to claim 1.   An electronic apparatus comprising any one of the organic EL device according to claim 1, the printer head according to claim 15, and the illumination device according to claim 16.

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