JP2008210671A - Organic electroluminescent device, method of manufacturing organic electroluminescent device, printer head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent device with improved emission characteristics and sealing characteristics, a method of manufacturing the same, and a printer head as well as an image forming apparatus with excellent electric characteristics. <P>SOLUTION: The organic electroluminescent device has a photocatalyst layer 37 formed at least between a wiring 242 and a hole transport layer 70 for enhancing its wettability with forming materials of the hole transport layer 70. The photocatalyst layer 37 is made of titanium oxide. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence device, an organic electroluminescence device manufacturing method, a printer head, and an image forming apparatus.

  A line printer (image forming apparatus) is known as an electrophotographic printer. In this line printer, devices such as a charger, a line-shaped printer head (line head), a developing device, and a transfer device are arranged close to each other on the peripheral surface of a photosensitive drum (photosensitive member) serving as an exposed portion. is there. An electrostatic latent image is formed on the peripheral surface of the photosensitive drum charged by the charger by selective light emission operation of the light emitting element provided in the printer head, and this latent image is developed. The toner image is developed with toner supplied from the container, and the toner image is transferred onto the paper by the transfer device.

  In order to obtain high-definition printing, it is necessary to efficiently image light emitted from the printer head on the photosensitive drum. Therefore, a technique has been proposed in which a lens array including a plurality of lens elements is provided between the printer head and the photosensitive member, and the light from the printer head is focused on the photosensitive member to form an image. As a lens array used in such a line printer, one having a plurality of lens elements or one having two rows in a staggered pattern is known.

In recent years, printer heads using an organic electroluminescence device (hereinafter referred to as an organic EL device) having a configuration in which an organic electroluminescence element (hereinafter referred to as an organic EL device) is provided on a glass substrate have been developed. In this organic EL device, an organic EL element is provided for each pixel, and wiring such as a data line and a scanning line connected to each organic EL element is provided (for example, see Patent Document 1). In general, an insulating film, an organic functional layer, or the like is formed on wirings such as data lines and scanning lines. As a method for forming the insulating film, the organic functional layer, and the like, a spin coat method in which the entire surface is coated on a substrate is well known. In addition, there is a photocatalyst-containing intermediate layer composed of a photocatalyst and a binder, and a selective coating is performed on the formation region of the organic EL element with a difference in wettability (see, for example, Patent Documents 2 to 4).
JP 2002-246293 A Japanese Patent Application Laid-Open No. 2002-172761 JP 2002-127783 A JP 2004-55177 A

  However, when an insulating film, an organic functional layer, or the like is formed on the wiring by spin coating, the flow is blocked by the side of the wiring when the liquid composition containing the forming material diffuses on the substrate. Become. For example, the liquid composition flows smoothly in a region where the extension direction of the wiring and the flow direction of the liquid composition are parallel, but the region where the extension direction of the wiring and the flow direction of the liquid composition are orthogonal is the liquid composition. It becomes difficult to flow. For this reason, the film thickness of the layer becomes nonuniform between the region where the liquid composition easily flows and the region where the liquid composition does not easily flow. If this film thickness is not uniform, the film thickness of each layer formed on the insulating layer and the cathode protective layer is also affected. For this reason, there exists a problem that a light emission characteristic and a sealing characteristic fall.

  In view of the circumstances as described above, an object of the present invention is to provide an organic electroluminescence device and a method for manufacturing the organic electroluminescence device that can improve the light emission characteristics and the sealing characteristics. Another object of the present invention is to provide a printer head and an image forming apparatus having excellent electrical characteristics.

In order to achieve the above object, an organic electroluminescence device according to the present invention is formed so as to cover an organic electroluminescence element including an organic functional layer on a substrate, a wiring connected to the organic electroluminescence element, and the wiring. In the organic electroluminescence device having the functional layer, a photocatalytic layer is formed at least between the wiring and the functional layer.
According to this configuration, since the photocatalyst layer is formed on the wiring, wettability can be improved between the wiring and the functional layer. Thereby, when the functional layer is formed by the liquid phase method, the material for forming the functional layer easily spreads on the wiring, so that the entire film thickness can be made uniform. Therefore, uniform light emission of the organic electroluminescence element can be obtained, and the sealing characteristics can be improved. In addition, as a result of the uniform light emission, it is possible to prevent a local current load from being applied to the organic functional layer of the organic electroluminescence element, thereby extending the life of the organic electroluminescence element.

The photocatalyst layer is preferably made of titanium oxide.
According to this configuration, it is possible to form a chemically stable photocatalyst layer having high band gap energy.

On the other hand, the organic electroluminescence device manufacturing method according to the present invention is formed so as to cover an organic electroluminescence element including an organic functional layer on a substrate, a wiring connected to the organic electroluminescence element, and the wiring. A method of manufacturing an organic electroluminescent device having a functional layer, the step of forming a photocatalyst layer covering at least the wiring, and forming the functional layer on the substrate on which the photocatalyst layer is formed by a liquid phase method And a process.
According to this configuration, by forming the photocatalyst layer on the wiring, the wettability can be improved between the wiring and the functional layer. Therefore, when the functional layer forming material is applied by the liquid phase method, The difference in coating speed caused by the difference in angle between the layer forming material and the wiring can be reduced. Thereby, the functional layer can be smoothly spread on the wiring and the entire film thickness can be made uniform. Therefore, uniform light emission of the organic electroluminescence element can be obtained, and the sealing characteristics can be improved. Further, as a result of the uniform light emission, it is possible to prevent a local current load from being applied to the organic functional layer of the organic electroluminescence element, and to manufacture a long-life organic electroluminescence element.
Furthermore, since the photocatalyst layer is formed at least on the wiring, the coating speed of the functional layer can be improved as a whole.

Moreover, before forming the said functional layer, it has the process of carrying out the UV cleaning of the said photocatalyst layer, and the process of carrying out the spin cleaning of the said photocatalyst layer, It is characterized by the above-mentioned.
According to this configuration, the oxygen atoms on the surface are desorbed by the holes generated by the photocatalytic effect, and an oxygen-deficient state is obtained. Then, the substrate is spin-cleaned to adsorb hydroxyl groups and increase the hydroxyl density on the surface. Thereby, the wettability on the wiring of a board | substrate can be improved.

The photocatalyst layer is preferably made of titanium oxide.
According to this configuration, it is possible to form a chemically stable photocatalyst layer having high band gap energy.

Further, the functional layer is formed by a spin coating method.
According to this configuration, when the spin coat method is used, the functional layer forming material diffuses from the center toward the outer peripheral direction, and thus film thickness unevenness is likely to occur, but between the wiring and the functional layer. Since the photocatalyst layer is formed on the wiring, the functional layer forming material can be smoothly spread on the wiring. Therefore, it is possible to improve the productivity by using the spin coating method while preventing the uneven thickness of the functional layer.

On the other hand, a printer head according to the present invention comprises the above organic electroluminescence device.
An image forming apparatus according to the present invention includes the printer head. According to this configuration, by applying the organic electroluminescence device to a printer head, uniform light emission can be obtained, and an image forming apparatus having excellent electrical characteristics and a long life can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. The present embodiment shows a part of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in each figure shown below, in order to make each layer and each member the size which can be recognized on drawing, the scale is varied for each layer and each member.

(Image forming device)
First, the image forming apparatus will be described. FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus.
As shown in FIG. 1, the image forming apparatus IM includes a head device 100 used as an exposure unit, a photosensitive drum 9, a corona charger 42 that uniformly charges the outer peripheral surface of the photosensitive drum 9, and a head. A developing device 44 that applies toner as a developer to the electrostatic latent image formed by the device 100 to form a toner image, a transfer roller 45 to which the toner image developed by the developing device 44 is transferred, and a transfer roller 45, a pressure roller 66 for transferring the toner image to the recording medium P, a fixing unit 61 for fixing the toner image to the recording medium P, and the toner remaining on the surface of the photosensitive drum 9 after the transfer. And a control device (not shown) for controlling the rotational drive of the photosensitive drum 9, the drive of the head device 100, and the like.

  The photosensitive drum 9 has a configuration in which a photosensitive layer as an image carrier made of an organic material or an inorganic material is provided on the outer peripheral surface of a base made of a conductive substance. Further, the photosensitive drum 9 is rotated clockwise in FIG. 1 and exposed by light from the head device 100 to form a latent image. The position in the rotation direction is detected by the encoder 9A and controlled. Output to the device. The rotation of the photosensitive drum 9 is controlled by a rotation driving device (not shown) under the control of the control device.

  The developing device 44 uses, for example, a non-magnetic one-component toner as a developer, and the one-component developer is conveyed to the developing roller by a supply roller, for example, and the film thickness of the developer adhered to the developing roller surface is regulated by a blade And the developer roller is brought into contact with or pressed against the photosensitive drum 9 to attach a developer according to the potential level of the photosensitive drum 9 and develop it as a toner image.

  The head device 100 includes head modules (line head modules) 101 and 102 arranged along the peripheral surface of the photosensitive drum 9 with a space between the corona charger 42 and the developing device 44. . The head modules 101 and 102 are disposed along the bus line of the photosensitive drum 9.

FIG. 2 is a perspective sectional view of the head module according to the present embodiment.
As shown in FIG. 2, the head modules 101 and 102 of the present embodiment combine the line head 1 in which a plurality of organic EL elements (organic electroluminescence elements) are arranged and the light from the line head 1 at an equal-magnification ratio. An SL array (lens array) 31 in which lens elements to be imaged are arranged and a line head (printer head) 1 and a head case 52 that holds the outer periphery of the SL array 31 are configured. The line head 1 and the SL array 31 are held in the head case 52 in an aligned state, whereby the SL array 31 concatenates the light from the line head 1 to a photosensitive drum (described later) at an equal magnification. It is supposed to be imaged.

FIG. 3 is a diagram schematically showing the line head.
As shown in FIG. 3, the line head 1 is an embodiment of the organic EL device (organic electroluminescence device) of the present invention. As a light emitting device in the present invention, the line head 1 is formed on a long and thin rectangular element substrate 2. Of the drive elements 4 under the control of a light emitting element array 3A formed by arranging a plurality of organic EL elements 3, a drive element group including drive elements 4 for driving the organic EL elements 3, and a control device as a light emission control device. This is an organic EL device integrally formed with a control circuit group 5 for controlling driving. In FIG. 3, the light emitting element array 3 </ b> A is displayed by one organic EL element 3, but actually, the organic EL elements (organic electroluminescence elements) 3 are arranged in two lines, and these are arranged in a staggered manner ( (See FIG. 4 (a)).

  The organic EL element 3 includes at least an organic functional layer between a pair of electrodes. A power supply line 8 is connected to one electrode of the organic EL element 3, and a power supply line 7 is connected to the other electrode via a drive element 4. The drive element 4 is composed of a switching element such as a thin film transistor (TFT). When a TFT is adopted as the drive element 4, the power supply line 8 is connected to the source region, and the control circuit group 5 is connected to the gate electrode. The control circuit group 5 controls the operation of the drive element 4, and the drive element 4 controls the energization of the organic EL element 3.

  The configuration of such an organic EL element 3 will be further described in detail. FIG. 4A is a schematic view showing an organic EL element array of a line head, and FIG. 4B is a cross-sectional view taken along the line AA. In FIG. 4A, the layers above the photocatalyst layer on the wiring are omitted for easy understanding.

  As shown in FIG. 4B, when the organic EL element 3 is a so-called bottom emission type in which the light emitted from the light emitting layer 60 is emitted from the pixel electrode 23 side, the light is emitted from the element substrate (substrate) 2 side. Since it is the structure which takes out light, the transparent or semi-transparent thing is employ | adopted as the element substrate 2. FIG. For example, glass, quartz, resin (plastic, plastic film) and the like can be mentioned, and a glass substrate is particularly preferably used.

In the case of a so-called top emission type in which the organic EL element 3 emits light emitted from the light emitting layer 60 from the cathode (counter electrode) 50 side, from the sealing substrate side that is the opposite side of the element substrate 2. Since it becomes the structure which takes out emitted light, both a transparent substrate and an opaque substrate can be used. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.
In the present embodiment, a bottom emission type is adopted, and therefore transparent glass is used for the element substrate 2.

A base protective layer (not shown) mainly composed of silicon dioxide (SiO ₂ ) is formed on the surface of the element substrate 2 as a base, and the surface of the base protective layer is extended from the power line 7 described above. A wiring 242 is formed. An interlayer insulating layer 283 made of silicon dioxide (SiO ₂ ) or the like is formed on the surfaces of the wiring 242 and the base protective layer so as to cover the wiring 242 and the base protective layer. On the interlayer insulating layer 283, the organic EL element 3 is provided.

The organic EL element 3 includes an organic functional layer 40 sandwiched between the pixel electrode 23 and the cathode 50. The organic functional layer 40 includes a hole transport layer (functional layer) 70 and a light emitting layer 60.
Under such a configuration, the organic EL element 3 supplies current from the pixel electrode 23 and the cathode 50 to the light emitting layer 60, thereby causing holes injected from the hole transport layer 70 and electrons from the cathode 50. Are combined in the light emitting layer 60 to emit light.

  The pixel electrode 23 functioning as an anode injects holes into the hole transport layer 70 by an applied voltage. In the present embodiment, which is a bottom emission type, (Indium Tin Oxide) is used. The transparent conductive film is used.

  On the pixel electrode 23, an inorganic partition wall 25 and a photocatalyst layer 37 described later are stacked. The inorganic partition wall 25 and the photocatalyst layer 37 have an opening 25a that forms the same surface in cross-sectional view on the pixel electrode 23, and each of the light-emitting element rows 3A in which a plurality of organic EL elements 3 are arrayed is separated. To do. The photocatalyst layer 37 may be formed so as to recede from the inorganic partition wall 25 in a sectional view.

The inorganic partition wall 25 is formed of an insulating inorganic material such as silicon dioxide (SiO ₂ ). In addition, as a material for forming the inorganic partition wall 25, a combination of an inorganic material and an organic material may be used.

The hole transport layer 70 is for injecting / transporting the holes of the pixel electrode 23 to the light emitting layer 60. As a material for forming the hole transport layer 70, an aqueous dispersion of 3,4-polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) is particularly preferably used.
In addition, as a forming material of the positive hole transport layer 70, various things can be used, without being limited to the said thing. For example, a material obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as the aforementioned polystyrene sulfonic acid can be used.

  The light emitting layer 60 generates fluorescence by combining holes injected from the pixel electrode 23 through the hole transport layer 70 and electrons injected from the cathode 50. As a material for forming the light emitting layer 60, a known light emitting material capable of emitting fluorescence or phosphorescence is used. In the present embodiment, for example, a light emitting layer whose emission wavelength band corresponds to red is adopted. Of course, a light emission layer whose emission wavelength band corresponds to green or blue may be adopted. In this case, the photoconductor used has sensitivity in the light emitting region.

  Specific examples of the material for forming the light emitting layer 60 include (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), and polyvinylcarbazole (PVK). ), Polythiophene derivatives, and polysilanes such as 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 50 is formed so as to cover the light emitting layer 60, and is a metal having a low work function that can efficiently inject electrons into the light emitting layer 60, such as aluminum (Al), magnesium (Mg), gold ( Au), silver (Ag), or a metal material such as calcium (Ca). On the cathode 50, a sealing substrate is attached via a seal layer (adhesive layer) (not shown).

Thus, on the element substrate 2, the hole transport layer 70 and the light emitting layer 60 are formed from the pixel electrode 23 side in the opening 25 a formed in the inorganic partition wall 25 and the photocatalyst layer 37, that is, in the pixel region. The organic functional layer 40 is formed by laminating in this order.
On the other hand, a contact hole 283a is formed in the interlayer insulating layer 283, and the pixel electrode 23 is connected to the wiring 242 described above in the contact hole 283a.

  As shown in FIG. 4A, in the line head 1, a plurality of wirings 242 connected to each pixel electrode 23 extend, and a region in which the plurality of wirings 242 extends is a wiring line. The area 36 is configured. Each wiring 242 is connected to the power supply line 7 via each driving element 4 described above. In the wiring region 36, the interlayer insulating layer 283 and the inorganic partition wall 25 described above are stacked on the wiring 242.

Here, a photocatalytic layer 37 is formed on the inorganic partition wall 25 in the wiring region 36. This photocatalyst layer 37 is for improving the wettability of the surface of the wiring region 36, and is formed over the entire surface of the wiring region 36 excluding the pixel region of the organic EL element 3. Examples of the material for forming the photocatalyst layer 37 include titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), which are known as optical semiconductors, Examples thereof include metal oxides such as bismuth oxide (Bi ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ). In particular, titanium oxide (TiO ₂ ) has high band gap energy, is chemically stable and has toxicity. It is suitable because it is not easily available.

  Note that inclined portions may be formed on both side surfaces of the wiring 242 in the extending direction. Specifically, an inclined surface having a predetermined angle (for example, 30 degrees) is formed with respect to the formation surface of the wiring 242, and the interlayer insulating layer 283 and the inorganic partition wall 25 are laminated on the surface. And the photocatalyst layer 37 may be formed on the surface. Thereby, the level difference due to the unevenness of the wiring 242 is alleviated, the resistance when the material for forming the hole transport layer 70 is applied to the wiring region 36 can be reduced, and the material for forming the hole transport layer 70 can be reduced on the substrate 2. Can spread efficiently.

  FIG. 5 is a perspective view of the SL array. This SL array 31 is an arrangement (arrangement) of two rows of SL elements 31a having the same configuration as a SELFOC (registered trademark) lens element manufactured by Nippon Sheet Glass Co., Ltd. in a staggered manner. The gap between the SL elements 31a arranged in a staggered manner is filled with a black silicone resin 32, and a frame 34 is arranged around it.

The SL element 31a has a parabolic refractive index distribution from the center to the periphery. For this reason, the light incident on the SL element 31a travels while meandering in the constant cycle.
Therefore, if the length of the SL element 31a is adjusted, an image can be formed upright at an equal magnification. In the SL element 31a that forms an erecting equal-magnification image in this way, images formed by adjacent SL elements 31a can be superimposed, and a wide range of images can be obtained. Therefore, the SL array 31 shown in FIG. 5 can accurately form light from the entire line head 1.

(Line head manufacturing method)
Next, a method for manufacturing the line head 1 configured as described above will be described. Here, the process of forming the photocatalyst layer 37 on a mother substrate (hereinafter referred to as the substrate 2A) on which a plurality of line heads 1 are arranged will be described.
6 to 8 are process diagrams showing a method for manufacturing a line head.

As shown in FIG. 6A, a photocatalytic layer 37 is formed on the inorganic partition wall 25 on the wiring region 36. Specifically, after patterning the inorganic partition wall 25, a titanium oxide layer is formed by sputtering while mixing oxygen (O ₂ ) with titanium (Ti). Thereafter, titanium oxide (TiO ₂ ) is etched and patterned through a resist mask exposed and developed by a photolithography technique.
Subsequently, the substrate 2A on which titanium oxide (TiO ₂ ) is formed is UV-cleaned. Specifically, exposure is performed by irradiating light for exposure, for example, ultraviolet light (UV light). As a light source used for such exposure, conventionally known light sources such as a mercury lamp, a metal halide lamp, and a xenon lamp are used. In addition, the light irradiation amount at the time of exposure is set to an irradiation amount necessary for changing the characteristics by the action of a titanium oxide (TiO ₂ ) photocatalyst.

  As a result, oxygen atoms on the surface are desorbed by holes generated by the photocatalytic effect, resulting in an oxygen-deficient state. Here, the substrate 2A is subjected to ultrapure water spin cleaning, thereby adsorbing hydroxyl groups and increasing the hydroxyl group density on the surface. As a result, the wettability on the substrate 2A can be improved. Note that the photocatalyst layer 37 may be formed by patterning and stacking titanium (Ti), and then thermal oxidation.

  Next, as shown in FIG. 6B, a hole transport layer 70 is formed on the entire surface of the substrate 2A on which the photocatalytic layer 37 is formed. Specifically, as shown in FIG. 7, the material for forming the hole transport layer 70 described above is dropped onto the substrate 2A while rotating the substrate 2A (two-dot chain arrow in FIG. 7) by spin coating. . The dropped forming material (liquid composition) F diffuses over the entire surface of the substrate 2A.

  At this time, as shown in FIG. 8, the material for forming the hole transport layer 70 that diffuses in the direction along the extending direction of the wiring 242 flows smoothly along the wiring 242. Further, the material for forming the hole transport layer 70 that diffuses in the direction intersecting the extending direction of the wiring 242 also flows smoothly because the photocatalytic layer 37 that improves the wettability of the wiring 242 is formed. . As a result, the hole transport layer 70 having a uniform film thickness is formed.

Thereafter, the light emitting layer 60 is formed on the hole transport layer 70. Specifically, it is formed on the entire surface of the substrate 2A by a spin coat method, similarly to the material for forming the hole transport layer 70.
Thereafter, the cathode 50 is formed. Specifically, it can be formed by vapor deposition, sputtering, CVD, or the like. In particular, the vapor deposition method is preferable in that damage to the light emitting layer 60 due to heat can be prevented. As a result, a light emitting element array 3A in which a plurality of organic EL elements 3 are arranged is formed.

  Then, a sealing layer (adhesive layer) is formed on the cathode 50, and a sealing substrate (not shown) is further bonded by this sealing layer to perform sealing. Thereafter, the substrate 2A on which the line heads 1 are arranged is cut one by one (broken line in FIG. 7), whereby the line head 1 is completed.

  Here, a case where the photocatalyst layer 37 is not formed in the wiring region 36 will be described with reference to FIGS. FIG. 9 is a diagram showing the configuration of the line head when a photocatalyst layer is not formed in the wiring region as in the prior art, and FIG. 10 is a graph showing the film thickness variation for each pixel of the hole transport layer. Yes, the horizontal axis represents the pixel number, and the vertical axis represents the film thickness [Å]. Here, the pixel No. 0 to 300 correspond to the light emitting element 3 connected to the wiring 242 formed in the wiring region 36 on the right side in FIG. Reference numerals 300 to 500 correspond to the light emitting elements 3 connected to the wiring 242 formed in the left wiring region 36 in FIG.

  As shown in FIG. 9, in this configuration, when the hole transport layer 70 is formed on the wiring 242 by spin coating, the direction along the extending direction of the wiring 242 (pixel numbers 300 to 500 in FIG. 10). The material for forming the hole transporting layer 70 (liquid composition) that diffuses in () flows smoothly. On the other hand, the flow of the forming material (liquid composition) that diffuses in the direction intersecting with the extending direction of the wiring 242 (pixel Nos. 0 to 300 in FIG. 10) is hindered by the wiring 242. This is because when the substrate is applied by spin coating, the substrate 2A is rotated to diffuse the forming material, and a centrifugal force is applied to the forming material. Then, it is considered that when the forming material gets over the wiring 242, the centrifugal force is concentrated on the wiring 242, and the film thickness in the region intersecting the extending direction of the wiring 242 is locally increased. As a result, as shown in FIG. 10, the film thickness unevenness of the hole transport layer 70 occurs between the region along the extending direction of the wiring 242 and the region intersecting with the extending direction of the wiring 242. End up. This film thickness unevenness occurs at a maximum of about 180 [Å].

Thus, in this embodiment, the photocatalytic layer 37 made of titanium oxide (TiO ₂ ) is formed on the wiring region 36 where the wiring 242 extends. According to this configuration, in the wiring region 36, wettability can be improved between the inorganic partition wall 25 formed on the wiring 242 and the forming material of the hole transport layer 70. When the forming material is applied by a spin coating method, a difference in application speed caused by an angle between the wiring 242 and the forming material of the hole transport layer 70 can be reduced. Thereby, the forming material of the hole transport layer 70 can be smoothly spread on the wiring 242, and the entire film thickness can be made uniform.
Accordingly, uniform light emission of the organic EL element 3 can be obtained, and the sealing characteristics can be improved. Further, as a result of the uniform light emission, it is possible to prevent the local current load from being applied to the hole transport layer 70 of the organic EL element 3 and to prolong the life of the organic EL element 3. In addition, by forming the photocatalyst layer 37 to the same plane as the inorganic partition wall 25 in a sectional view, the organic EL element 3 is formed while ensuring the lyophilicity and element characteristics of the forming material of the hole transport layer 70. Can do.

  Furthermore, since the photocatalyst layer 37 is formed on the entire surface of the wiring region 36, the application speed of the material for forming the hole transport layer 70 can be improved as a whole. In addition, when the spin coating method is used, the functional layer forming material diffuses from the center toward the outer peripheral direction, and thus film thickness unevenness is likely to occur. However, since the photocatalyst layer 37 is formed, the wiring region The material for forming the hole transport layer 70 can be smoothly spread on the surface 36. Therefore, the line head 1 having excellent electrical characteristics can be efficiently manufactured by using the spin coating method.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. For example, the photocatalyst layer may be formed on the source electrode or the drain electrode as a matter of course.

  In addition, the organic EL device of each of the embodiments described above can be applied to a monochrome display. In addition, the light emitting layer (organic functional layer) of the organic EL device of each of the above-described embodiments is made of, for example, a white light emitting material, and light (white light) emitted from each pixel region is color-filtered. It is also possible to form a full color display by converting each of red light, green light and blue light.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. Perspective sectional view of a head module according to the present embodiment The top view which shows the structure of a line head. Schematic which shows the organic EL element row | line | column of a line head. The figure which shows the structure of a lens array. Process drawing which shows the manufacturing method of the line head which concerns on this embodiment. The process drawing. The process drawing. The figure which shows a mode that it forms into a film by the conventional spin coat method. The graph which shows the film thickness of the conventional positive hole transport layer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Line head 2 ... Element board | substrate (board | substrate) 2A ... Board | substrate 3 ... Organic EL element 50 ... Cathode 24 ... Wiring 40 ... Organic functional layer 70 ... Hole transport layer (functional layer)

Claims (8)

In an organic electroluminescence device having an organic electroluminescence element including an organic functional layer on a substrate, a wiring connected to the organic electroluminescence element, and a functional layer formed to cover the wiring,
An organic electroluminescence device, wherein a photocatalytic layer is formed at least between the wiring and the functional layer.   The organic electroluminescence device according to claim 1, wherein the photocatalyst layer is made of titanium oxide. An organic electroluminescent device comprising: an organic electroluminescent element including an organic functional layer on a substrate; a wiring connected to the organic electroluminescent element; and a functional layer formed to cover the wiring. ,
Forming a photocatalyst layer covering at least the wiring;
And a step of forming the functional layer by a liquid phase method on the substrate on which the photocatalyst layer has been formed. Before the functional layer is formed, UV cleaning the photocatalytic layer;
The method for producing an organic electroluminescence device according to claim 3, further comprising a step of spin cleaning the photocatalyst layer.   The method for manufacturing an organic electroluminescence device according to claim 3, wherein the photocatalyst layer is made of titanium oxide.   The method for manufacturing an organic electroluminescent device according to claim 3, wherein the functional layer is formed by a spin coating method.   A printer head comprising the organic electroluminescence device according to claim 1.   An image forming apparatus comprising the printer head according to claim 7.

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