JP2004006254A - El display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an EL display device having high reliability wherein the EL element is cut off from external moisture or the like and deterioration due to oxidation of EL layer can be prevented by a structure in which the EL element is completely encapsulated by means of a filler. <P>SOLUTION: A covering material 307 is adhered onto a glass substrate 301 wherein an EL element is formed using a filler 305 as an adhesive. A desiccant 306 is contained in the covering material. Furthermore, a sealant 309 is installed so as to conceal the side face (exposed face) of the filler 305 and a frame material 310 is adhered by using the sealant 309. Owing to this structure, since the EL element is completely filled by the filler 305 and cut off from the external moisture or the like, the deterioration by oxidation of the EL layer can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an EL (electroluminescence) display device and an electronic device using the same. Specifically, the present invention relates to a technique for preventing deterioration of an EL element.
[0002]
[Prior art]
In recent years, a display device (EL display device) using an EL element as a self-luminous element utilizing the EL phenomenon of an organic material has been developed. Since the EL display device is a self-luminous type, it does not require a backlight like a liquid crystal display device and has a wide viewing angle, so that it is promising as a display portion of a portable device used outdoors.
[0003]
However, since the EL layer, which is a basic part of the EL element, is made of an organic material, it is extremely susceptible to oxidation and easily deteriorates due to the presence of a small amount of oxygen. It is also weak to heat, which also promotes oxidation. This disadvantage of being susceptible to oxidation is the cause of the short lifetime of the EL element, and has been a major barrier to practical use.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a highly reliable EL display device. It is another object to provide an electronic device with high reliability of a display portion by using such an EL display device as a display portion.
[0005]
[Means for Solving the Problems]
The configuration of the present invention will be described with reference to FIG. FIG. 1A shows an EL display device of the present invention, in which a sealing structure for enclosing an EL element in a closed space is not provided.
[0006]
In FIG. 1A, 101 is a substrate, 102 is a pixel portion, 103 is a source side driver circuit, 104 is a gate side driver circuit, 105 is a pixel portion 102, a source side driver circuit 103, and a gate side driver circuit 104 are FPC ( This is a connection wiring for electrically connecting to a flexible print circuit (106). The FPC is electrically connected to an external device, so that an external signal can be input to the pixel portion 102, the source driver circuit 103, and the gate driver circuit 104.
[0007]
The pixel portion 102, the source side driver circuit 103, and the gate side driver circuit 104 are formed using thin film transistors (hereinafter, referred to as TFTs) formed over the substrate 101. Note that a TFT having any structure may be used as the TFT. Of course, a known structure may be used.
[0008]
FIG. 1B illustrates a state where a sealing structure is provided in the state illustrated in FIG. The sealing structure of the present invention includes a filler (not shown), a cover 107, a seal (not shown), and a frame 108.
[0009]
Here, FIG. 2A is a cross-sectional view taken along line AA ′ of FIG. 1B, and FIG. 2B is a cross-sectional view taken along line BB ′ of FIG. 2A and 2B, the same reference numerals are used for the same parts as those in FIGS. 1A and 1B.
[0010]
As shown in FIG. 2A, a pixel portion 102 and a driver circuit 103 are formed over a substrate 101. The pixel portion 102 includes a current control TFT 201 and a plurality of pixels including a pixel electrode 202 electrically connected thereto. Of pixels. This pixel electrode 202 functions as an anode of the EL element. An EL layer 203 is formed so as to cover the pixel electrode 202, and a cathode 204 of the EL element is formed thereon.
[0011]
Note that, in this specification, an element having a combination of anode / EL layer / cathode is referred to as an EL element. Actually, light is obtained by passing a current between the anode and the cathode and recombining electrons and holes in the EL layer.
[0012]
The structure of the EL element is not particularly limited in the present invention. Usually, a film having a high work function, for example, a transparent conductive film is used as the anode, and a film having a low work function, for example, a film containing an alkali metal or an alkaline earth metal is used as the cathode. Further, any known structure can be used for the EL layer.
[0013]
Note that in this specification, an EL layer refers to a layer which is provided between an anode and a cathode and provides a place where carriers move, transport, or recombine. Although it may be composed of only the light emitting layer which becomes the recombination center, it is usually used in combination with an electron injection layer, an electron transport layer, a hole injection layer or a hole transport layer.
[0014]
In addition, materials for forming the EL layer include an inorganic material and an organic material, and an organic material that requires a low driving voltage is preferable. Further, among the organic materials, there are a low molecular material and a high molecular (polymer) material, and the high molecular material is effective from the viewpoint of high heat resistance and easy film formation.
[0015]
By the way, the driving circuit 103 is formed at the same time when the pixel portion 102 is formed. The driving circuit 103 is often formed using a CMOS circuit in which an n-channel TFT 205 and a p-channel TFT 206 are complementarily combined as a basic unit.
[0016]
The cathode 204 also functions as a common wiring for all pixels, and is electrically connected to the FPC 106 via the connection wiring 105. Further, all elements included in the pixel portion 102 and the driving circuit 103 are covered with the passivation film 207. Although the passivation film 207 can be omitted, it is preferable to provide the passivation film 207 in order to isolate each element from the outside.
[0017]
Next, a filler 208 is provided so as to cover the EL element. This filler 208 also functions as an adhesive for bonding the cover 107. As the filler 208, PVC (polyvinyl chloride), epoxy resin, silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used. It is preferable to provide a desiccant inside the filler 208 because the moisture absorbing effect can be maintained.
[0018]
In addition, as the cover material 107, a glass plate, an aluminum plate, a stainless steel plate, an FRP (Fiberglass-Reinforced Plastics) plate, a PVF (polyvinyl fluoride) film, a mylar film, a polyester film, or an acrylic film can be used. When PVB or EVA is used as the filler 208, it is preferable to use a sheet having a structure in which aluminum foil of several tens of μm is sandwiched between PVF films or mylar films.
[0019]
However, depending on the direction of light emission (the direction of light emission) from the EL element, the cover material 107 needs to have translucency. That is, in the case of FIG. 2, the light is emitted to the opposite side of the cover material 107, and therefore the material is not limited. In the case of the emission to the cover material 107, the cover material 107 is made of a material having a high transmittance. Is desirable.
[0020]
Next, after bonding the cover member 107 with the filler 208, the frame member 108 is attached so as to cover the side surface (exposed surface) of the filler 208. The frame material 108 is bonded by a seal material (functioning as an adhesive) 209. At this time, a photocurable resin is preferably used as the sealant 209, but a thermosetting resin may be used as long as the heat resistance of the EL layer is allowed. Note that the sealant 209 is preferably a material that does not transmit moisture or oxygen as much as possible. Further, a desiccant may be added to the inside of the sealant 209.
[0021]
By enclosing the EL element in the filler 208 using the above method, the EL element can be completely shut off from the outside, and a substance which promotes deterioration of the EL layer due to oxidation such as moisture or oxygen from the outside can be obtained. Intrusion can be prevented. Therefore, a highly reliable EL display device can be manufactured.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view of the EL display device according to the present invention. Note that the basic structure is the same as that in FIG.
[0023]
In the EL display device in FIG. 3, a pixel portion 302 and a driver circuit 303 are formed using TFTs formed over a glass substrate 301. An EL element 304 is electrically connected to a current controlling TFT formed in the pixel portion 302. Note that a quartz substrate, a silicon substrate, a stainless steel substrate, a plastic substrate (including a plastic film), or a ceramic substrate may be used instead of the glass substrate. However, it is necessary to provide an insulating film on the substrate as needed.
[0024]
In the present embodiment, an EL layer having a high molecular weight organic material as a light emitting layer and an anode made of a transparent conductive film common to each pixel are formed on a pixel electrode (cathode) connected to the current control TFT. To form an EL element. As the high molecular weight organic material, any known material may be used, or a low molecular weight organic material may be laminated and used. Further, any known laminated structure may be used. In the present embodiment, a white light-emitting layer is formed on the cathode in accordance with JP-A-8-96959. As the transparent conductive film serving as the anode, a compound of indium oxide and tin oxide, a compound of indium oxide and zinc oxide, tin oxide, or zinc oxide can be used.
[0025]
PVB is provided as a filler 305 on the active matrix substrate having the above structure, and the filler 305 contains barium oxide as a desiccant 306. In addition to barium oxide, those described in JP-A-9-148066 can be used. The addition of the desiccant is not essential in the present invention, but is desirably added in order to further enhance the reliability.
[0026]
The desiccant may be added in any form, but if dispersed in a large lump (cluster shape), it may cause a decrease in image brightness. Is preferred. Preferably, a granular desiccant having an average diameter of 100 μmφ or less is 1 × 10 ² ~ 1 × 10 ⁵ Pieces / cm ³ Is preferably included at a density of
[0027]
A glass substrate is provided as a cover material 307 on the filler 305. In the case of the present embodiment, the cover member 307 must be translucent. This is because light emitted from the light emitting layer reaches the observer through the cover material 307 due to the structure of the EL element. Of course, a plastic substrate (including a plastic film), a quartz substrate, or a PVF film can be used as the cover member 307 instead of the glass substrate.
[0028]
In the present embodiment, the light-shielding film 308 and the color filter 309 are formed on the cover member 307. As the light-blocking film 308, a resin containing black pigment or carbon may be used. Of course, a metal film such as a titanium film, a tantalum film, or a tungsten film may be used. As the color filter 309, a resin containing a red, green, or blue pigment may be used. The light-shielding film 308 and the color filter 309 may be formed by a known method such as an inkjet method or a spin coating method.
[0029]
In the present embodiment, a white light-emitting layer is used as an EL element in a single layer, and white light emitted therefrom is separated into colors by a color filter to obtain red, green, and blue colors. This enables color display. The color display method that can be used in the present invention may be any known method. Further, not only color display but also monochrome display by monochromatic light emission is possible.
[0030]
Here, a method of bonding the cover member 307 using the filler 305 will be described with reference to FIGS. The apparatus shown in FIG. 4 is a bonding apparatus of a system called a double vacuum system. This bonding apparatus has a first vacuum chamber 401 and a second vacuum chamber 402, each of which is provided with a first exhaust unit 403, a second exhaust unit 404, a first leak valve 405, and a second leak valve 406. ing.
[0031]
Further, a heating means 407 is attached to the second vacuum chamber 402, and the temperature inside the first vacuum chamber 402 can be increased by resistance heating. Further, inside the second vacuum chamber 402, an active matrix substrate (substrate after completion of the formation of the TFT and the EL element) 408, a PVB film 409, and a cover material 410 are arranged.
[0032]
Next, first, the insides of the first vacuum chamber 401 and the second vacuum chamber 402 are evacuated to a vacuum. Then, in this state, the inside of the second vacuum chamber 402 is heated to about 120 ° C. by the heating means 407, so that the PVB film 409 exhibits fluidity. When the PVB film 409 shows fluidity, the leak valve 405 of the first vacuum chamber 401 is opened, and the inside of the first vacuum chamber 401 is released to the atmosphere and pressurized.
[0033]
When the first vacuum chamber 401 is pressurized, a diaphragm (formed of silicone, rubber, or the like) separating the first vacuum chamber 401 and the second vacuum chamber 402 presses the cover member 410 of the second vacuum chamber 402. Then, the active matrix substrate 408 and the cover member 410 are completely bonded by the filler 409. Thereafter, the second vacuum chamber 402 is returned to room temperature, and is released to the atmosphere by a leak valve 406. The second vacuum chamber 402 may be forcibly cooled by circulating cooling water or the like.
[0034]
As described above, the step of bonding the active matrix substrate and the cover material is performed. In this embodiment, the double vacuum system is used, but a single vacuum system may be used. Both techniques are described in detail in "Solar Cell Handbook, edited by the Institute of Electrical Engineers of Japan, Special Committee on Solar Cell Research, pp. 165-166, 1985".
[0035]
After the active matrix substrate and the cover member 307 are bonded with the filler 305 as described above, the frame member 310 is bonded with the sealant 309 to completely cover and hide the end surface of the filler 305. In this embodiment, an ultraviolet-curable epoxy resin is used as the sealing material 309, and a stainless steel material is attached as the frame material 310.
[0036]
Thus, an EL display device as shown in FIG. 3 is completed. In such an EL display device, since moisture and oxygen do not enter from the outside, deterioration of the EL layer can be prevented and the life of the EL element is long. That is, the EL display device is very reliable.
[0037]
【Example】
[Example 1]
In this embodiment, FIG. 5 shows an example in which a PVF film is used as a cover material. In FIG. 5, reference numeral 501 denotes a light-transmitting substrate (a plastic substrate in this embodiment), 502 denotes a pixel portion, and 503 denotes a driving circuit, each of which is formed by a TFT. An EL element 504 is formed in the pixel portion 502, and an image is displayed.
[0038]
A cover member 507 is attached via a filler 505 to which a desiccant 506 is added on the active matrix substrate formed up to the EL element (or a passivation film thereon). In the bonding step, a bonding apparatus shown in FIG. 4 may be used. The cover member 507 has a structure in which an aluminum foil (aluminum foil) 507c is sandwiched between PVF films 507a and 507b. The aluminum foil 507c is provided for improving moisture resistance.
[0039]
Thereafter, a frame member 509 is attached using a seal member 508 made of an ultraviolet curable resin. In this embodiment, a stainless steel material is used as the frame material 509. Finally, the FPC 510 is attached to complete the EL display device.
[0040]
[Example 2]
In this embodiment, FIG. 6 shows an example in which the present invention is applied to a simple matrix EL display device. In FIG. 6, reference numeral 601 denotes a plastic substrate; 602, a cathode having a laminated structure of an aluminum film and a lithium fluoride film (a portion in contact with the EL layer is a lithium fluoride film). In this embodiment, the cathode 602 is formed by an evaporation method. Although not shown in FIG. 6, a plurality of cathodes are arranged in stripes in a direction perpendicular to the plane of the drawing.
[0041]
On the cathode 602, an EL layer (only the light emitting layer) 603 made of a polymer organic material is formed by a printing method. In the present embodiment, PVK (polyvinyl carbazole), Bu-PBD (2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-oxadiazole), coumarin 6 , DCM1 (4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran), TPB (tetraphenylbutadiene) and Nile Red are dissolved in 1,2-dichloromethane, and printed on the cathode 602 by a printing method. Then, baking is performed to form a white light-emitting EL layer 603.
[0042]
In this embodiment, the EL layer 603 has a single-layer structure including only the light-emitting layer. However, if necessary, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, an electron blocking layer, or a hole may be used. An element layer may be provided.
[0043]
After forming the EL layer 603, an anode 604 made of a transparent conductive film is formed. In this embodiment, a compound of indium oxide and zinc oxide is formed as a transparent conductive film by an evaporation method. Although not shown in FIG. 6, a plurality of anodes are arranged in a stripe shape such that the longitudinal direction is the direction perpendicular to the plane of the paper and is orthogonal to the cathodes. In addition, although not shown, wiring is drawn out to the portion where the FPC is attached later so that a predetermined voltage is applied to the anode 604.
[0044]
After the formation of the anode 604, a 100-nm-thick silicon nitride film is formed as the passivation film 605. This is a protective film for preventing the EL layer 604 from contacting the outside air when a cover material or the like is bonded later.
[0045]
An EL element is formed over the substrate 601 as described above. Next, a plastic plate is prepared as a cover material 606, and a light-shielding film 607 and a color filter 608 are formed on the surface of the plastic plate. The light-blocking film 607 uses a resin containing carbon, and the color filter 608 uses a resin containing a pigment corresponding to RGB. As a film formation method, an inkjet method, a spin coating method, or a printing method may be used.
[0046]
In the structure of this embodiment, the light emitted from the EL element passes through the cover member 606 and enters the eyes of the observer, so that the cover member 606 is translucent. Although a plastic plate is used in this embodiment, a light-transmitting substrate (or a light-transmitting film) such as a glass plate or a PVF film may be used.
[0047]
After preparing the cover material 606 in this way, the cover material 606 is bonded via the filler 610 to which the desiccant 609 is added. In the bonding step, a bonding apparatus shown in FIG. 4 may be used. Thereafter, a frame member 612 is attached using a seal member 611 made of an ultraviolet curable resin. In this embodiment, a stainless steel material is used as the frame material 612. Finally, the FPC 613 is attached to complete the EL display device.
[0048]
[Example 3]
In this embodiment, FIG. 7 shows an example in which the present invention is applied to a simple matrix EL display device. In FIG. 7, reference numeral 701 denotes a glass substrate, and 702 denotes an anode made of a transparent conductive film. In this embodiment, a compound of indium oxide and tin oxide is formed by a sputtering method. Although not shown in FIG. 7, a plurality of anodes are arranged in stripes in a direction perpendicular to the plane of the drawing.
[0049]
An insulating film (silicon nitride film in this embodiment) 703 is formed on the anode 702 by photolithography, and a spacer 704 made of a resin such as acrylic or polyimide is formed on the insulating film 703. The spacer 704 is formed to have an inverted triangle. To form an inverted triangle, a resin film serving as a spacer may be provided in a laminated structure, and a lower layer may have a higher etching rate. The spacer 704 is formed in a stripe shape whose longitudinal direction is perpendicular to the paper surface.
[0050]
After the formation of the spacer 704, the EL layer 705 and the cathode 706 are continuously formed by a vapor deposition method without breaking vacuum. The EL layer 705 has a structure in which CuPc (copper phthalocyanine) having a thickness of 30 nm, TPD (triphenylamine derivative) having a thickness of 50 nm, and Alq (tris-8-quinolinolato aluminum complex) having a thickness of 50 nm are stacked from the anode side. . However, the film thickness is not limited to this. As the cathode 706, an MgAg (alloy co-evaporated at a ratio of Mg: Ag = 10: 1) electrode having a thickness of 120 nm is used. Thus, a green light emitting EL element is formed.
[0051]
Since the EL layer 705 and the cathode 706 are deposited using a shadow mask, the EL layer 705 and the cathode 706 can be selectively formed without being formed in unnecessary portions. In the pixel portion, the pixels 707 are separated from each other by the spacer 704, so that the pixels 707 can be integrated at a high density. Of course, the EL layer 705 and the cathode 706 are formed in a stripe shape along the spacer 704 with the longitudinal direction perpendicular to the plane of the drawing. In this structure, the cathode 706 is arranged so as to be orthogonal to the anode 702.
[0052]
After forming up to the cathode 706 without breaking the vacuum, an electrode made of an aluminum film is formed as the protection electrode 708 without breaking the vacuum. The protection electrode 708 functions as a conductor for uniformly applying a voltage to the cathode 706, and also functions as a protection film for preventing the oxidation of the cathode 706. Although not shown, the protective electrode 708 is electrically connected so that the same voltage can be applied to all the cathodes, and a wiring is drawn out to a portion where an FPC is attached later so that a predetermined voltage is applied. .
[0053]
An EL element is formed over the substrate 601 as described above. Next, a cover member 711 is attached via a filler 710 to which a desiccant 709 is added. In the bonding step, a bonding apparatus shown in FIG. 4 may be used. Thereafter, a frame member 713 is attached using a seal member 712 made of an ultraviolet curable resin. In this embodiment, a stainless steel material is used as the frame material 713. Finally, the FPC 714 is attached to complete the EL display device.
[0054]
In the structure of this embodiment, since the light emitted from the EL element is emitted to the opposite side of the cover member 711, the cover member 606 may be translucent or light-blocking. Although a glass plate is used as the cover member 711 in this embodiment, a plastic plate, a light-transmitting substrate (or a light-transmitting film) such as a PVF film or a ceramic plate, a film in which an aluminum foil is sandwiched between PVFs, or the like is used. good.
[0055]
[Example 4]
Since the EL display device formed by implementing the present invention is a self-luminous type, it has better visibility in a bright place than a liquid crystal display device, and has a wide viewing angle. Therefore, it can be used as a display portion of various electronic devices. For example, in order to watch a TV broadcast or the like on a large screen, the EL of the present invention is used as a display unit of an EL display (a display in which an EL display device is incorporated in a housing) with a diagonal of 30 inches or more (typically, 40 inches or more). A display device is preferably used.
[0056]
The EL display includes all displays for displaying information, such as a display for a personal computer, a display for receiving a TV broadcast, and a display for displaying an advertisement. In addition, the EL display device of the present invention can be used as a display portion of various electronic devices.
[0057]
Such electronic devices of the present invention include a video camera, a digital camera, a goggle type display (head mounted display), a car navigation system, a sound reproducing device (car audio, audio component, etc.), a notebook personal computer, a game machine, A portable information terminal (mobile computer, mobile phone, portable game machine, electronic book, or the like), an image reproducing device provided with a recording medium (specifically, a compact disk (CD), a laser disk (LD), or a digital video disk (DVD) ), Etc.), and a device provided with a display capable of reproducing the recording medium and displaying the image. In particular, it is desirable to use an EL display device for a portable information terminal, which is often viewed from an oblique direction, since importance is placed on the wide viewing angle. FIG. 8 shows specific examples of these electronic devices.
[0058]
FIG. 8A illustrates an EL display, which includes a housing 2001, a support 2002, a display portion 2003, and the like. The present invention can be used for the display portion 2003. Since the EL display is a self-luminous type, it does not require a backlight and can be a display portion thinner than a liquid crystal display.
[0059]
FIG. 8B illustrates a video camera, which includes a main body 2101, a display portion 2102, an audio input portion 2103, operation switches 2104, a battery 2105, an image receiving portion 2106, and the like. The EL display device of the present invention can be used for the display portion 2102.
[0060]
FIG. 8C illustrates a part (right side) of a head-mounted EL display, which includes a main body 2201, a signal cable 2202, a head fixing band 2203, a display portion 2204, an optical system 2205, an EL display device 2206, and the like. Including. The present invention can be used for the EL display device 2206.
[0061]
FIG. 8D illustrates an image reproducing apparatus (specifically, a DVD reproducing apparatus) including a recording medium, a main body 2301, a recording medium (CD, LD, DVD, or the like) 2302, an operation switch 2303, and a display unit (a). 2304, a display unit (b) 2305, and the like. The display unit (a) mainly displays image information, and the display unit (b) mainly displays character information. The EL display device of the present invention can be used for these display units (a) and (b). Note that the image reproducing device provided with the recording medium may include a CD reproducing device, a game device, and the like.
[0062]
FIG. 8E illustrates a portable computer, which includes a main body 2401, a camera portion 2402, an image receiving portion 2403, operation switches 2404, a display portion 2405, and the like. The EL display device of the present invention can be used for the display portion 2405.
[0063]
FIG. 8F illustrates a personal computer, which includes a main body 2501, a housing 2502, a display portion 2503, a keyboard 2504, and the like. The EL display device of the present invention can be used for the display portion 2503.
[0064]
If the emission luminance of the EL material is increased in the future, the light including the output image information can be enlarged and projected by a lens or the like and used for a front-type or rear-type projector.
[0065]
In addition, the electronic devices often display information distributed through electronic communication lines such as the Internet and CATV (cable television), and in particular, opportunities to display moving image information are increasing. Since the response speed of the EL material is very high, the EL display device is preferable for displaying a moving image. However, if the outline between pixels is blurred, the entire moving image is also blurred. Therefore, it is extremely effective to use the EL display device of the present invention, which makes the outline between pixels clear, as a display portion of an electronic device.
[0066]
Further, in the EL display device, since the light emitting portion consumes power, it is desirable to display information so that the light emitting portion is reduced as much as possible. Therefore, when an EL display device is used for a portable information terminal, particularly a display portion mainly for character information such as a mobile phone or a sound reproducing device, the character information is formed by a light emitting portion with a non-light emitting portion as a background. It is desirable to drive.
[0067]
Here, FIG. 9A illustrates a mobile phone, which includes a main body 2601, an audio output unit 2602, an audio input unit 2603, a display unit 2604, operation switches 2605, and an antenna 2606. The EL display device of the present invention can be used for the display portion 2604. Note that the display portion 2604 can reduce power consumption of the mobile phone by displaying white characters on a black background.
[0068]
FIG. 9B illustrates an audio reproducing device, specifically, a car audio, which includes a main body 2701, a display portion 2702, and operation switches 2703 and 2704. The EL display device of the present invention can be used for the display portion 2702. Further, in this embodiment, a car audio system is shown, but it may be used in a portable sound reproducing apparatus. Note that the display portion 2704 can reduce power consumption by displaying white characters on a black background. This is particularly effective in a portable sound reproducing device.
[0069]
As described above, the applicable range of the present invention is extremely wide, and the present invention can be used for electronic devices in all fields. Further, the electronic device of this embodiment may use the EL display device having any of the structures shown in the first to seventh embodiments.
[0070]
【The invention's effect】
By implementing the present invention, it is possible to effectively suppress deterioration of the EL element portion of the EL display device. Therefore, a highly reliable EL display device can be obtained. In addition, by using such a highly reliable EL display device as a display portion of an electronic device, the reliability of the electronic device can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a top structure of an EL display device.
FIG. 2 illustrates a cross-sectional structure of an EL display device.
FIG. 3 illustrates a cross-sectional structure of an EL display device.
FIG. 4 is a view showing a double vacuum bonding apparatus.
FIG. 5 illustrates a cross-sectional structure of an EL display device.
FIG. 6 illustrates a cross-sectional structure of an EL display device.
FIG. 7 illustrates a cross-sectional structure of an EL display device.
FIG. 8 illustrates a specific example of an electronic device.
FIG. 9 illustrates a specific example of an electronic device.

Claims (9)

A driving circuit and a pixel portion formed on the substrate,
A pixel electrode electrically connected to the current controlling TFT of the pixel portion;
An EL element comprising the pixel electrode, an EL layer, and a cathode;
A filler covering the EL element;
Having a cover material bonded to the filler,
An EL display device, wherein the filler contains a desiccant. A driving circuit and a pixel portion formed on the substrate,
A pixel electrode electrically connected to the current controlling TFT of the pixel portion;
An EL element comprising the pixel electrode, an EL layer, and a cathode;
A passivation film covering the EL element;
A filler covering the EL element and the passivation film;
Having a cover material bonded to the filler,
An EL display device, wherein the filler contains a desiccant. 3. The EL display device according to claim 1, further comprising: a sealing material that covers a side surface of the filler, and a frame material bonded by the sealing material. 4. The EL display device according to claim 1, wherein the cover member has a light-transmitting property. The EL display device according to any one of claims 1 to 4, wherein a light shielding film or a color filter is provided on the cover member. The drying agent according to any one of claims 1 to 5, wherein the desiccant is in the form of particles having an average diameter of 100 µmφ or less, and is contained in the filler at a density of 1 × 10 ² to 1 × 10 ⁵ / cm ³ . An EL display device, characterized in that: The EL display device according to any one of claims 1 to 6, wherein the desiccant is barium oxide. An electronic device, wherein the EL display device according to any one of claims 1 to 7 is used for a display unit. A mobile phone using the EL display device according to any one of claims 1 to 7 for a display unit.

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