JP4392656B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device that displays information visually and an electronic apparatus including the electro-optical device.

  In the field of electro-optical devices, there is a problem of a method for radiating heat generated from an electro-optical element, a drive circuit of the electro-optical element, etc. from the viewpoint of improving durability of an electro-optical layer of a display panel that generates light modulated by information. It has become. For example, an organic EL element constituting an organic electroluminescence (EL) display includes an inorganic anode, an organic light emitting layer as an electro-optical layer, an inorganic cathode, and the like, and the organic light emitting layer is generally easily affected by heat. The heat generated from the organic light emitting layer itself and the drive circuit by energization accumulates in the display panel, thereby causing a decrease in luminance and light emission efficiency. Moreover, the organic light emitting layer is also affected by the intrusion of oxygen or moisture, and problems such as the generation of non-light emitting parts may occur.

  In order to solve these problems, for example, Japanese Patent Application Laid-Open No. 2002-343559 attaches a metal heat sink having fins on a second electrode that does not extract light as a heat radiating member, and releases heat to the atmosphere. Proposed method.

Also, for example, Japanese Patent Application Laid-Open No. 2003-22891 is a method in which a hollow structure is formed by a lower substrate and a sealing substrate, and a heat radiating part formed on the surface facing the sealing substrate of the second electrode is provided inside the hollow structure. is suggesting.
JP 2002-343559 A JP 2003-22891 A

  However, the heat dissipation method described above involves an increase in weight and volume of the electro-optical device due to the addition of a metal heat sink and a hollow structure. This impairs the advantages of lightness, thinness, and smallness, which are the characteristics of flat panel displays such as organic EL displays, plasma displays, and surface electroluminescent displays that are electro-optical devices.

  Accordingly, an object of the present invention is to provide an electro-optical device having a structure with an excellent heat dissipation effect without sacrificing the light and thin advantages of flat panel displays.

  Another object of the present invention is to protect the electro-optical device from heat associated with light emission and improve its durability.

  Another object of the present invention is to provide an electronic apparatus having a heat-resistant electro-optical device and improved reliability.

  In order to achieve the above object, an electro-optical device of the present invention is an electro-optical device that displays information visibly, a display panel that displays an image by arranging electro-optical elements constituting pixels, and the display panel And a hydrophilic layer that adsorbs moisture on at least one surface.

According to the above structure, the hydrophilic layer formed on the outermost surface of the electro-optical device adsorbs moisture in the atmosphere to form a thin water layer. The moisture evaporates due to the heat generation of the electro-optical device, thereby removing the heat of vaporization and releasing the generated heat of the electro-optical device into the atmosphere. In particular, by uniformly forming a hydrophilic layer on the surface of the electro-optical device including at least the display region, moisture in the atmosphere can be uniformly adsorbed on the surface of the electro-optical device on which the hydrophilic layer is formed. . As a result, the heat generated by the electro-optical device can be uniformly dissipated, and deterioration of the display quality of the electro-optical device due to moisture adsorbed on the electro-optical device, for example, local diffused reflection of light due to moisture can be prevented. Can do. Moreover, since it does not depend on a heat sink or a hollow structure, the heat dissipation can be improved without sacrificing the advantages of lightness, thinness, and smallness, which are the features of flat panel displays.
As a result, the reliability of the electro-optical device can be improved.

  The hydrophilic layer is a material made of a transparent metal oxide. The above material contains an oxide semiconductor material whose energy band gap is 3 eV to 6 eV as a main component. Specifically, the metal oxide is mainly composed of any one of titanium, zinc, tin, and indium.

  According to the above materials, by using a metal oxide having an energy band gap of 3 eV to 6 eV for the hydrophilic layer, it is possible to obtain translucency without absorption of visible light, and a heat dissipation function is also provided on the display side of the display. You can have it. Furthermore, the above material is suitable in terms of antifouling effect and antibacterial effect due to the photocatalytic function. It is a metal oxide having an energy band gap of 3 eV to 6 eV, and has a photocatalytic function, thereby efficiently transmitting visible light from the electro-optical element, and exhibiting photocatalytic activity by ultraviolet rays such as external light, The wettability of the hydrophilic layer can be improved, and moisture in the atmosphere can be efficiently adsorbed to the hydrophilic layer.

  The electro-optical device further includes a sealing layer (or a blocking layer) having a gas barrier property that prevents at least moisture from passing between the hydrophilic layer and the electro-optical element.

  Accordingly, moisture and oxygen can be prevented from entering the electro-optical element, and the durability of the electro-optical device can be improved.

  The sealing layer is a silicon compound.

  According to the above material, by using a silicon compound that is transparent, moisture-proof, and excellent in chemical stability, it is possible to prevent the light-emitting layer and the electrode from being deteriorated by moisture, and to improve the durability of the electro-optical device.

  In addition, a gas layer or a substrate that inhibits heat transfer by having a structure in which the sealing layer does not have a hollow portion, or a structure in which a substrate such as a glass substrate is not interposed between the electro-optic element and the hydrophilic layer. The heat generated in the electrode wiring and the organic light emitting layer can be quickly transferred to the hydrophilic layer, and the heat dissipation can be further improved.

  The hydrophilic layer is provided on both surfaces of the display panel.

  Thereby, the heat dissipation effect can be further improved.

  The electro-optical device includes a supply source of moisture to be adsorbed on the hydrophilic layer.

  Thereby, the water | moisture content can be continuously supplied to a hydrophilic layer, and the thermal radiation effect can be continued.

  The moisture supply source is a fuel cell that supplies power to the display panel.

  This is preferable because the water discharged from the fuel cell can be used.

  The water supply source is a substance having moisture retention.

  This is preferable because moisture discharged from the moisture-retaining substance can be used.

  The present invention is an electronic apparatus including the above-described electro-optical device in a display unit. Here, the electronic device generally includes a device having a circuit board and other elements and having a certain function, and the configuration thereof is not particularly limited. Electronic devices include, for example, IC cards, mobile phones, video cameras, personal computers, head mounted displays, rear or front projectors, televisions (TVs), roll-up TVs, and fax machines with display functions. Examples include digital camera finders, portable TVs, PDAs, electronic notebooks, electronic bulletin boards, and advertising displays.

  First, points of interest of the present invention will be described.

  As mentioned above, in order to improve the durability of organic EL displays, heat dissipation means and sealing layers have been proposed, but as the display becomes larger, thinner and lighter, the panel strength can withstand external stress. In order to maintain, it is necessary to switch from a hollow structure to a solid structure having a thin film laminated structure. In addition, as the size of the panel increases, heat generated inside the panel must be released due to improved brightness and higher wiring density, and a thin heat dissipation layer is provided to replace the heavy metal heat sink. There is a need. Furthermore, it is necessary to use a top emission structure that emits light from the opposite side of the circuit board in order to sufficiently secure the area of the switching TFT and the wiring circuit as the size increases. Therefore, it is necessary to take a thin structure that is transparent, lightweight and excellent in strength resistance, and a structure excellent in heat dissipation is required.

  In recent years, SiOx, SiNx, and AlOx thin films that are transparent and have excellent gas barrier properties called thin film sealing have been studied, and high-density plasma film forming methods (ion plating, ECR plasma sputtering, ECR plasma) using a high-density plasma source have been studied. By using CVD, surface wave plasma CVD, ICP-CVD, etc., a thin film gas barrier layer that completely blocks moisture can be formed. However, the heat dissipation of this gas barrier layer is not sufficient.

  Therefore, as a result of various studies, by providing a transparent hydrophilic layer on the outermost surface of the sealing layer composed of a gas barrier layer, it is possible to dissipate heat on the light emitting surface side, which could only be done from the non-light emitting surface side of the conventional panel. It turned out that it becomes. Furthermore, it has also been found that by using these also on the non-light emitting surface side, it is possible to manufacture a thin and lightweight panel with good heat dissipation without using a large heat sink.

  Various electro-optic materials such as liquid crystal and EL materials can be applied to the electro-optic elements constituting the display panel. In addition, the electro-optic element can be configured not only as a single layer but also as a laminated film of a plurality of functional layers. For example, a plurality of functional layers including a hole injection layer, a hole transport layer, an EL light-emitting layer, an electron transport layer, an electron injection layer, and the like are stacked between the first electrode and the second electrode. Thus, an EL light emitting element can be formed as an electro-optical element. In particular, in the case of an element that exhibits a function when carriers supplied from the first electrode or the second electrode pass through the EL layer, such as an EL light-emitting element, the existence probability of electrons and holes is at least partially. Different portions may be generated, and the charge balance of the portions may be lost. Such a portion is generally highly reactive, and reacts with, for example, oxygen or water to form a structural defect (that is, a carrier trapping site), which causes a decrease in the function of the electro-optic layer. For this reason, the effect which provides a gas barrier layer is large compared with what expresses a function by other methods.

  The electro-optical device of the present invention is an electro-optical device having an electro-optical element formed by sequentially laminating at least a first electrode, an electro-optical layer, and a second electrode on a substrate, and is the outermost surface of the display panel. Has a hydrophilic layer.

  In this device, since the hydrophilic layer is formed on the outermost surface of the solid sealing layer (blocking layer), the heat generated in the organic light emitting layer and the wiring is transmitted to the sealing layer, and the outermost hydrophilic layer is formed. It is transmitted to the sex layer. The hydrophilic layer attracts water vapor present in the atmosphere to form a thin water layer on the surface. And when it evaporates again by the rise in panel temperature, it takes away the heat which a panel has as vaporization heat, and evaporates. And the water | moisture content in air | atmosphere adsorb | sucks again by the fall of surface temperature. By repeating such adsorption and evaporation of water, an increase in panel temperature can be prevented.

  In addition, since the sealing layer does not have a hollow portion, heat can be easily transferred, and heat generated in the thin sealing layer wiring or the organic light emitting layer can be quickly transferred to the hydrophilic layer, improving heat dissipation. be able to.

  The hydrophilic layer is intended to impart heat dissipation to the light emitting surface and needs to have transparency. Therefore, a metal oxide such as an oxide semiconductor material having an energy band gap of 3 eV to 6 eV is used. It is preferable to use it as a main component. By providing a sealing layer and a hydrophilic layer that easily transmit heat, a top emission panel with excellent heat dissipation can be created. Note that a material having an energy band gap of less than 3 eV absorbs visible light, and thus cannot be used for a top emission structure that requires translucency. Therefore, it is desirable that the main component is an oxide semiconductor material having an energy band gap of 3 eV to 6 eV.

  The hydrophilic layer is preferably a material having photocatalytic activity. When these layers are excited by light of the organic light-emitting layer or external light, the outermost surface of the layer exerts a strong catalytic action and brings about a cleaning effect on the panel surface. Even if impurities such as sebum adhere to the panel surface, these deposits are decomposed and removed by the catalytic action, and the surface of the hydrophilic layer can always be kept clean.

Examples of such a material having photocatalytic activity include titanium oxide (TiO ₂ ), strontium titanate (SrTiO ₃ ), zinc oxide (ZnO), tungsten oxide (WO ₃ ), tin oxide (SnO ₂ ), niobium oxide ( Nb ₂ O ₆ ), potassium tantalate (KTaO ₃ ), iron oxide (Fe ₂ O ₃ ), indium oxide (In ₂ O ₃ ) and other oxide semiconductors are known, and the hydrophilic layer of the present invention is also used. The above-mentioned material can be used as a main component, but considering that photocatalytic activity can be relatively easily obtained, the hydrophilic layer contains a light-transmitting oxide containing any of titanium, zinc, tin, and indium. It is desirable that the main component is a physical semiconductor material.

  In order to improve the heat dissipation performance of the hydrophilic layer as much as possible, it is necessary to shorten the heat conduction time by reducing the distance from the organic light emitting layer or wiring on the substrate side to the hydrophilic layer as much as possible. Therefore, it is necessary to reduce the thickness of the sealing layer. For example, it is preferable to use a thin gas barrier layer to form a thin sealing layer structure.

  As a gas barrier layer having a gas barrier function, which is one of the purposes of the sealing layer, it is preferable to form a silicon compound such as silicon oxide, silicon nitride, or silicon oxynitride by the high-density plasma film forming method. Further, the gas barrier layer may be formed after providing a buffer layer made of an organic material in order to flatten irregularities such as the organic light emitting layer and the pixel partition wall and prevent cracks and pinholes in the gas barrier layer. In particular, since silicon nitride or silicon oxynitride containing nitrogen forms a dense film, barrier properties against oxygen and moisture are improved.

  The surface of the gas barrier layer may be protected with a resin or a protective film in order to protect the gas barrier layer from external physical damage such as scratches and drop impacts, and these are also included in the sealing layer.

  Even if the gas barrier layer is not used, a transparent glass substrate may be bonded with an adhesive or the like to form a sealing layer. In this case, in consideration of heat dissipation, it is preferable to use a glass substrate that is as thin as possible, and a manufacturing method in which pressure bonding is performed under reduced pressure is preferable in order to remove bubbles that enter the adhesive during bonding.

  A plurality of adhesives may be used in order to increase the moisture resistance of the adhesive used for bonding. For example, an adhesive with high translucency may be used for the light emitting surface, and an opaque adhesive to which inorganic particles are added with priority given to moisture resistance may be used for the peripheral portion.

  Furthermore, in order to further improve moisture resistance, a gas barrier layer and a glass substrate may be used in combination. In this case, the buffer layer, the gas barrier layer, the protective layer, and the glass substrate are combined to form a sealing layer.

  An electro-optical device of the present invention is manufactured by the above-described manufacturing method, and is characterized in that a first electrode, an electro-optical layer, a second electrode, a sealing layer, and a hydrophilic layer are sequentially stacked on a substrate. . With this configuration, the life of the apparatus can be extended.

  According to another aspect of the present invention, there is provided an electronic apparatus including the above-described electro-optical device. Thereby, an increase in panel temperature can be prevented, and an electronic device having excellent durability can be provided.

  Furthermore, the electro-optical device of the present invention is characterized by including a supply source of moisture to be adsorbed on the hydrophilic layer. Thereby, heat radiation can be continuously performed even in a dry atmosphere.

  For example, it is preferable to use water discharged from the fuel cell used to drive the electro-optical device of the present invention. Alternatively, a material having moisture retention may be disposed in the vicinity of the electro-optical device of the present invention as a moisture supply source.

  A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory view illustrating the structure of an organic EL display device as an example of the electro-optical device of the present invention.

  In the organic EL display device of this example, an insulating layer 101 is formed on an electrically insulating substrate 100 as shown in the figure, and a switching TFT (thin film transistor) 102 is formed in the insulating layer 101 via a wiring 103. A connected pixel electrode 104 as a first electrode is arranged in a matrix on the substrate 100 (not shown), and is arranged around the pixel electrode area and each pixel. The active matrix driving type is configured to include a power supply line (not shown) connected to the electrode 104 and a substantially rectangular pixel portion in plan view located on the pixel electrode area.

  FIG. 2 shows an example of an active matrix driving circuit. In the figure, an active matrix driving circuit 200 includes a signal line driving circuit 21 that outputs a video signal, a scanning line driving circuit 22 that outputs a scanning pulse, and the like. The signal electrode lines X1, X2, X3,... Are connected to the signal line drive circuit 21, and the scan electrode lines Y1, Y2, Y3,. A pixel electrode region 23 is formed together with C). In the pixel electrode region 23, a first TFT 24 and a second TFT 25 are made of polysilicon or the like. Electrical switching is performed by the first TFT 24, and driving is performed by applying a current to the organic light emitting layer 27 by the second TFT 25 and the capacitor 26. However, as the effect of the present invention, the same effect can be obtained even in a passive matrix drive type having a switching element and a circuit outside the substrate.

  On the pixel electrode 104, an organic light-emitting layer 105 as an electro-optical layer is arranged in a matrix in the form of red, green, and blue, separated from each other by a bank layer (or pixel partition wall layer) 106 vertically and horizontally. Has been. Further, a cathode 107 as a second electrode, a cathode protective layer 108, a buffer layer 109, and a gas barrier layer 110 are sequentially laminated on the organic light emitting layer 105, and then a protective substrate 112 is further laminated via the protective layer 111. To do. Then, a hydrophilic layer 113 having a heat dissipation effect is formed on the outermost surface of the protective substrate 112.

  In the case of a so-called top emission type organic EL display device, the substrate 100 is configured to extract display light from the sealing layer side that is the opposite side of the substrate 100, so that either a transparent substrate or an opaque substrate can be used. it can. Examples of opaque substrates include ceramics such as alumina, metal sheets such as aluminum, and silicon substrates that have been subjected to insulation treatment such as surface oxidation, and polyimide films, plastic films such as thermosetting resins and thermoplastic resins, and the like. It is done. In the case of a bottom emission type organic EL display device, since the display light is extracted from the substrate 100 side, a transparent or translucent substrate is employed as the substrate 100. For example, glass, quartz, a translucent plastic film, etc. are mentioned, and generally a glass substrate having excellent heat resistance is preferably used. In the present embodiment, a top emission type in which emitted light is extracted from the sealing layer side is used.

  Under such a configuration, the light emitting element emits light from the organic light emitting layer 105 by combining holes injected from the anode and the hole transport layer and electrons injected from the cathode and the electron transport layer. It has come to produce.

  Since the pixel electrode 104 is a top emission type in this example, it does not need to be transparent, and may be a highly conductive metal such as aluminum, titanium, or copper, or a metal oxide conductive layer such as ITO (indium tin oxide). good. Therefore, it is formed of an appropriate conductive material.

  As a material for forming the cathode 107, since this embodiment is a top emission type, it needs to be light transmissive, and therefore a metal oxide conductive material having good light transmissive property is used. ITO (indium tin oxide) is preferably used as the transparent conductive material, but other metal oxides such as indium zinc oxide, aluminum zinc oxide, and tin oxide can be used.

  In addition, a low resistance metal film such as aluminum, gold, or silver may be used as a thin film as long as the transparency is not lowered, and these are preferably used in bottom emission. Furthermore, these may be laminated and used in consideration of transparency and a decrease in electric resistance.

  A sealing layer is formed on the cathode 107 so as to cover the cathode 107. The sealing layer needs to be as thin as possible in consideration of heat dissipation. For example, it is preferable to form a transparent thin film having a gas barrier property made of a silicon compound by a high density plasma film forming method.

  The gas barrier layer 110 needs to form a high-density and extremely hard film in order to block moisture and oxygen. For this reason, if a structure such as the bank layer 106 or the pixel partition wall is directly covered, cracks and pinholes are likely to occur. By providing a buffer layer 109 made of an organic material covering these structures, particles, and the like, Defects in the gas barrier layer 110 to be formed can be prevented. The buffer layer 109 is preferably made of an organic material, and flatness can be obtained by forming it by a wet process such as a slit die coater. This prevents oxygen and moisture from entering the electron injection layer and the organic light emitting layer 105 and suppresses these alterations.

  A protective layer 111 made of a resin material is provided on the gas barrier layer 110. The protective layer 111 is intended to protect the gas barrier layer 110 and is included in the sealing layer. The constitution may be a single layer such as an overcoat layer or a two-layer structure in which an adhesive layer and a protective film are combined. As the adhesive layer, an adhesive made of a transparent resin material such as an epoxy resin, an acrylic resin, a urethane resin, or a silicone resin can be suitably used. Moreover, in order to harden | cure at low temperature, the 2 liquid mixing type which adds hardening | curing agents, such as isocyanate, may be sufficient.

  Next, a protective substrate 112 is provided on the protective layer 111. As the protective substrate 112, glass, a transparent plastic film (PET, acrylic, polycarbonate, polyolefin, etc.) or the like can be used. For the bonding, a method of pressure bonding while reducing pressure is more preferable in order to prevent mixing of bubbles. The protective substrate 112 is also treated as a part of the sealing layer.

  In the present embodiment, the hydrophilic layer 113 is formed on the outermost surface of these sealing layers. The hydrophilic layer 113 serves as a heat dissipation layer that releases heat with the heat of the display when moisture adsorbed on the surface evaporates. Any material can be used as long as it adsorbs moisture in the atmosphere. However, in view of surface cleanliness and transparency, it is preferable to use a metal oxide material having photocatalytic activity. . Specifically, a metal oxide material having an energy band gap of 3 eV to 6 eV is preferable. Examples include titanium oxide (3.2 eV), zinc oxide (3.2 eV), tin oxide (3.5 eV), and indium oxide (3.8 eV). Since a part of (such as blue light) is blocked, it cannot be used for the top emission type. However, when used in the bottom emission type, since transparency is not required, a metal material such as aluminum can be used for the hydrophilic layer.

  As a hydrophilic index, it can be represented by a contact angle (θ) with water shown in FIG. The contact angle is expressed as an angle at which water drops when the water is dropped on the surface of a solid object to be measured. It can be said that the lower the contact angle, the easier the water spreads and the more hydrophilic it is. Titanium oxide (10 degrees) and tin oxide (22 degrees) are extremely hydrophilic with a contact angle of 30 degrees or less. Moreover, since it has photocatalytic activity, it can be excited by external light or emitted light to decompose contaminants such as organic substances and sebum on the surface. Furthermore, by using a material of 6 eV or less for the hydrophilic layer, ultraviolet light on the short wavelength side that decomposes the organic material or the like can be blocked, so that ultraviolet light contained in sunlight can also be blocked.

  As the material of the hydrophilic layer 113, titanium oxide, which has a contact angle with water that is reduced by external light irradiation and is excellent in photocatalytic activity, is used. As a formation method, in consideration of photocatalytic activity and adhesion to a protective layer, it is preferable to form the film by a high-density plasma film formation method, similarly to the gas barrier layer. Alternatively, the hydrophilic layer 113 may be formed by diluting titanium oxide fine particles with a solvent and applying and drying with a slit die coater or the like. The film thickness is 50 to 2000 nm.

  Next, the effect of the present embodiment will be described based on experimental results. In this embodiment, a TV image is continuously displayed on a 14-inch size full-color organic EL display (active matrix drive) for 10 minutes in a windless environment with a temperature of 25 ° C. and a humidity of 50%, and the temperature at the center of the display is measured. The effect of was confirmed. The temperature at the center of the display was 98 ° C. when no hydrophilic layer was present, but it was 60 ° C. when titanium oxide was formed as the hydrophilic layer of this example. From the results of this experiment, it was confirmed that the effect of the present invention that the temperature rise during driving of the organic EL display can be suppressed and the amount of heat of the electro-optical device is reduced. As a result, deterioration of characteristics due to heat generation such as deterioration of the light emitting layer and the electrode can be suppressed, and the life of the light emitting element can be extended.

  In addition, since titanium oxide has a photocatalytic effect, there is also an effect that the surface of the hydrophilic layer can be kept clean by decomposing organic substances such as sebum adhering to the surface of the organic EL display.

  A second embodiment will be described with reference to FIG. FIG. 4 is an explanatory view illustrating the structure of an organic EL display device as an example of the electro-optical device of the present invention. In FIG. 4, portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and description of such portions is omitted. To do. In the second embodiment, the buffer layer and the gas barrier layer employed in the structure of the organic EL display device of the first embodiment are omitted, and instead the substrate side surface is sealed with glass.

  Specifically, a protective layer 111 made of a resin material is formed so as to cover the cathode protective layer 108, and a protective substrate 112 is provided thereon. Note that glass is used for the protective substrate 112.

  Next, the sealing member 301 is disposed around the substrate side surface through the adhesive layer 302 to seal the substrate side surface. Since the adhesive forming the adhesive layer 302 does not require transparency, an adhesive with high moisture resistance that contains a large amount of inorganic particles can be used. Then, a hydrophilic layer 113 is formed on the outermost surface of the protective substrate 112. In this embodiment, tin oxide is formed by a high density plasma film forming method.

  With this structure, it is possible to improve the sealing performance by suppressing the intrusion of oxygen and moisture from the side surface. Moreover, the temperature rise at the time of the drive of an organic EL display can be suppressed by the heat dissipation effect from a hydrophilic layer. As a result, deterioration of characteristics due to heat generation such as deterioration of the light emitting layer and the electrode can be suppressed, and the life of the light emitting element can be extended.

  Moreover, since tin oxide has a photocatalytic effect, there is also an effect that organic substances such as sebum adhering to the surface of the organic EL display can be decomposed to keep the surface of the hydrophilic layer clean.

A third embodiment will be described with reference to FIG. FIG. 5 is an explanatory view illustrating the structure of an organic EL display device as an example of the electro-optical device of the present invention. In FIG. 5, portions corresponding to those in FIG. To do. In the third embodiment, a hydrophilic layer as a heat dissipation layer is provided on both sides of the display panel.

  Specifically, the hydrophilic layer 401 is provided on the outermost surface of the substrate 100 opposite to the first electrode of the substrate 100 in the first embodiment. Specifically, as described in Example 1, a metal oxide material having an energy band gap of 3 eV to 6 eV is preferable. In this embodiment, titanium oxide having an energy band gap of 3.2 eV is used as a material. As a forming method, a high density plasma film forming method is used.

  The effect of the present embodiment will be described based on experimental results. In this embodiment, a TV image is continuously displayed on a 14-inch size full-color organic EL display (active matrix drive) for 10 minutes in a windless environment with an air temperature of 25 ° C. and a humidity of 50%, and the temperature at the center of the display is measured. The effect of was confirmed. The temperature at the center of the display was 98 ° C. when no hydrophilic layer was present, but it was 50 ° C. in this example. From the results of this experiment, it was confirmed that the effect of the present invention that the temperature rise during driving of the organic EL display can be suppressed and the amount of heat of the electro-optical device is reduced. As a result, deterioration of characteristics due to heat generation such as deterioration of the light emitting layer and the electrode can be suppressed, and the life of the light emitting element can be extended.

  In addition, since titanium oxide has a photocatalytic effect, there is also an effect that the surface of the hydrophilic layer can be kept clean by decomposing organic substances such as sebum adhering to the surface of the organic EL display.

  A fourth embodiment will be described with reference to FIG. FIG. 6 is a perspective view showing a notebook personal computer as an electronic apparatus equipped with the electro-optical device of the present invention.

  In the fourth embodiment, a fuel cell built in a notebook computer is used as a supply source of moisture to be adsorbed on the hydrophilic layer of the electro-optical device of the present invention.

  In FIG. 6, electric energy necessary for operating the notebook personal computer or driving the electro-optical device 500 of the present invention is supplied from the fuel cell 501. As the fuel cell 501, for example, when a solid polymer fuel cell using hydrogen reformed from methanol as a raw material is used, water vapor is generated together with electric energy by an electrochemical reaction between hydrogen and air (oxygen). The water vapor is diffused upward from the radiation hole 503 via the conduit 502 and is adsorbed by the hydrophilic layer of the electro-optical device 500 of the present invention.

  As in this embodiment, the heat radiation effect can be maintained even in a dry environment by providing a moisture supply source.

  A fifth embodiment will be described with reference to FIG. FIG. 7 is a perspective view showing a mobile phone as an electronic apparatus equipped with the electro-optical device of the present invention.

  In the fifth embodiment, a substance having water retention capacity is disposed in the vicinity of the electro-optical device as a supply source of moisture to be adsorbed to the hydrophilic layer of the electro-optical device of the present invention.

  Specifically, as shown in FIG. 7, a substance 601 having water retention properties is arranged in a frame shape in the vicinity of the electro-optical device 600, for example, along the outer periphery. The substance is, for example, a polymer compound having moisture retention. Moisture evaporated from the water-retaining substance is adsorbed on the hydrophilic layer.

  By taking the form as in this embodiment, the heat dissipation effect can be maintained even in a dry environment.

  An electronic apparatus including the electro-optical device according to the present invention in a display unit will be described with reference to FIG. FIG. 8 is a diagram illustrating a specific example of an electronic apparatus including the above-described electro-optical device.

  FIG. 8A shows an application example to a mobile phone. The mobile phone 230 includes an antenna portion 231, an audio output portion 232, an audio input portion 233, an operation portion 234, and the electro-optical device 700 of the present invention. . As described above, the electro-optical device according to the invention can be used as a display unit. FIG. 8B shows an application example to a video camera. The video camera 240 includes an image receiving unit 241, an operation unit 242, an audio input unit 243, and the electro-optical device 700 of the present invention. FIG. 8C shows an application example to a television, and the television 300 includes the electro-optical device 700 of the present invention. The electro-optical device according to the present invention can be similarly applied to a monitor device used for a personal computer or the like. FIG. 8D shows an application example to a roll-up television, and the roll-up television 310 includes the electro-optical device 700 of the present invention. Further, the electronic device is not limited to these, and can be applied to various electronic devices having a display function. For example, in addition to these, a fax machine with a display function, a finder for a digital camera, a portable TV, an electronic notebook, an electric bulletin board, a display for advertising, etc. are also included. The circuit board according to the present invention can be applied alone as a component part of an electronic device, in addition to the case where it is included in the electronic device as described above as a component part of an electro-optical device.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the top emission type structure using the active matrix substrate is described as an example of the electro-optical device. However, the present invention is not limited to this, and the bottom emission type is also provided on both sides. The present invention can also be applied to a type that emits display light. Moreover, since the same effect is acquired even if it is an active matrix type and a passive matrix type, it is applicable to both.

It is sectional drawing explaining the structure of the organic electroluminescent display apparatus (electro-optical apparatus) in a 1st Example. It is a circuit diagram explaining the mechanism of the active matrix drive circuit of an organic EL display device (electro-optical device). It is explanatory drawing for demonstrating a contact angle. It is sectional drawing explaining the structure of the organic electroluminescence display in a 2nd Example. It is sectional drawing explaining the structure of the organic electroluminescence display in a 3rd Example. It is a perspective view which shows embodiment of this invention in a 4th Example. It is a perspective view which shows embodiment of this invention in a 5th Example. It is explanatory drawing explaining the example of the electronic device which uses an electro-optical apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Signal line drive circuit, 22 ... Scanning line drive circuit, 23 ... Pixel electrode area, 26 ... Capacitor, 100 ... Substrate, 101 ... Insulating layer, 24, 25, 102 ... Thin film transistor, 103 ... Wiring, 104 ... Pixel electrode, 27, 105 ... organic light emitting layer, 106 ... bump layer, 107 ... cathode, 108 ... cathode protective layer, 109 ... buffer layer, 110 ... gas barrier layer, 111 ... protective layer, 112 ... protective substrate, 113, 401 ... hydrophilic layer , 301, sealing member, 302, adhesive layer, 500, 600, 700, electro-optical device of the present invention, 501, fuel cell, 502, conduit, 503, diffusion hole, 601, substance having water retention property, 230, portable. Telephone, 231 ... Antenna unit, 232 ... Audio output unit, 233 ... Audio input unit, 234 ... Operation unit, 240 ... Video camera, 241 ... Image receiving unit, 242 ... Operation unit, 243 An audio input portion, 300 ... television, roll-up television

Claims (11)

An electro-optical device for displaying an image,
A display panel in which electro-optic elements constituting pixels are arranged;
A hydrophilic layer formed on at least one surface of the display panel to adsorb moisture;
A sealing layer that is formed between the electro-optic element and the hydrophilic layer and has a gas barrier property that prevents the passage of moisture;
An electro-optical device, wherein heat of the display panel is released by heat of vaporization of moisture adsorbed on the hydrophilic layer.   The electro-optical device according to claim 1, further comprising a supply source of moisture to be adsorbed on the hydrophilic layer in the vicinity of the display panel.   3. The electro-optical device according to claim 2, wherein the moisture supply source is a fuel cell that supplies power to the display panel.   The electro-optical device according to claim 2, wherein the moisture supply source is a substance having moisture retention.   The electro-optical device according to claim 1, wherein the hydrophilic layer is made of a transparent metal oxide.   6. The electro-optical device according to claim 5, wherein the metal oxide is mainly composed of an oxide semiconductor material having an energy band gap of 3 eV to 6 eV.   The electro-optical device according to claim 5, wherein the metal oxide is mainly composed of any one of titanium, zinc, tin, and indium.   The electro-optical device according to claim 1, wherein the sealing layer is a silicon compound.   The electro-optical device according to claim 1, wherein the sealing layer is formed of a glass substrate.   The electro-optical device according to claim 1, wherein the hydrophilic layer is provided on both surfaces of the display panel.   An electronic apparatus comprising the electro-optical device according to claim 1 in a display unit.

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