JP2001332392A - Double-sided organic electroluminescent device, double-sided organic electroluminescent display device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic EL element which emits light on both surfaces and which is able to project pictures on both surfaces by a display unit being composed of such a both-faced luminous organic EL element, the display device 1 and an electronic equipment using this. SOLUTION: In the organic EL element wherein the both-faced luminous organic EL element 1A is constituted so that an electron carrier layer 6, an organic luminous layer 5 and a positive hole carrier layer 4 are laminated from the side of the cathode electrode 7 between the opaque cathode electrode 7 and the transparent anode electrode 3, a transparent light-conducting part is constituted to be formed at feast in a part of the opaque cathode electrode 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided organic electroluminescence device using an organic compound (hereinafter, "electroluminescence device" is simply referred to as "EL device"), a display device using the same, and an electronic device using the same. It concerns equipment.

[0002]

2. Description of the Related Art First, a general organic EL device of the prior art will be described with reference to the drawings.

FIG. 9 is a conceptual perspective view of a general organic EL device of the prior art, and FIG. 10 is an organic EL device shown in FIG.
It is a schematic diagram of an element.

[0004] In FIG. 9, reference numeral 1 denotes a conventional organic E.
L element. In the case of the drawing, only the organic EL element 1 of two pixels is shown. This organic EL element 1 generally has
A thin hole transport layer 4 is formed on a transparent anode electrode 3 formed on a transparent glass substrate 2, and the hole transport layer 4
The light emitting layer 5 is formed by laminating a fluorescent substance, a thin electron transport layer 6 is formed thereon, and a metal cathode electrode 7 is formed thereon. Here, “transparent” refers to a light transmitting property capable of sufficiently transmitting light from the light emitting layer.

The anode electrode 3 (transparent electrode) can be formed of, for example, tin-doped indium oxide (ITO), and the cathode electrode 7 is a metal electrode having a small work function such as Mg. , MgA
g, MgIn and the like are used. As the light emitting layer 5, for example, an organometallic complex dye such as tris (8-quinolinolato) aluminum can be used. The light emitting layer 5 may also serve as the electron transport layer 6, and in such a case, tris (8-quinolinolato) aluminum or the like is used. Further, as the hole transport layer 4, for example, tetraphenyldiamine (TPD) can be used.

These layers can be patterned by a method such as etching after mask evaporation or film formation, if necessary, to obtain a desired light emitting pattern. The cathode electrode 7 is formed by such patterning. Further, the substrate is a thin film transistor (TFT), and by forming each layer (thin film) according to the pattern, the display device and the driving device can be used as they are, and the surface thereof is made of an inorganic material such as SiOX, Teflon. The display device may be protected by forming a protective layer with an organic material such as (registered trademark). Organic EL device 1
For example, the thickness of the glass substrate 2 is about 1 mm, and the total thickness of all parts except the glass substrate 2 is 1.5 to 2 m.
m.

The organic EL element 1 is connected to a DC power source
A DC voltage of about 0 V can be applied to perform DC driving, but AC driving or pulse driving can also be used. When the voltage is applied, the light emitting layer 5 emits light, and the light is emitted from the anode electrode 3 side as shown by an arrow since the cathode electrode 7 has no light transmitting property. Therefore, such organic E
Even if a display device is formed by the L element 1, an image can be displayed only on one surface, and its use is limited.

[0008]

For this reason, attempts have been made to extract the light emitted from the organic EL element from both the cathode electrode and the anode electrode, and Mg / Ag is formed on the light emitting layer. One using a cathode electrode on which ITO is laminated is known. The material used as the cathode electrode of the organic EL element is preferably a material capable of injecting a large amount of electrons into the light emitting layer, and the material having a smaller work function is better.

However, Mg.Ag and ITO as described above are used.
In the case of a cathode electrode using ITO, since the ITO does not have a low resistance in a film after being formed, the efficiency is reduced. ITO
In order to reduce the resistance at room temperature, heat treatment must be further performed, but the heat treatment damages the organic EL element and impairs the light emitting function.

Therefore, since a transparent electrode which is preferable as a cathode electrode has not been put to practical use, a double-sided emission type organic EL device has been proposed.
The element and the display device using the same have not been put to practical use at present.

Therefore, in an electronic device with a display device such as a notebook personal computer (notebook personal computer) having a keyboard as a main body and a display device also serving as a lid, the display device is usually provided with a keyboard. When closed on the main body side, images cannot be displayed on the display device.

An object of the present invention is to solve such a problem, and it is possible to project an image on both sides by forming a display device with double-sided light emitting organic EL elements. It is an object of the present invention to obtain a possible organic EL element, a display device and an electronic device using the same.

[0013]

Therefore, in the first invention, a double-sided light emitting organic EL element is provided between an opaque cathode electrode and a transparent anode electrode, from the cathode electrode side, from the electron transport layer, to the organic EL element. In an organic EL device formed by laminating a light emitting layer and a hole transport layer, at least a part of the opaque cathode electrode is formed of a transparent member as a light guide, thereby solving the above-mentioned problem.

In the second invention, a double-sided light emitting organic E
An L display device is configured by arranging a plurality of double-sided organic EL elements of the first invention on a transparent substrate at predetermined intervals,
The above problem has been solved.

According to a third aspect of the present invention, there is provided an electronic apparatus comprising: a main body in which main components are disposed; and a lid which becomes a lid on a surface of the main body when closed. The double-sided light emitting type organic EL display device is provided, and the double-sided light emitting type organic EL display is provided on the main body and / or the lid.
The object is solved by providing an image inverting means for inverting an image projected on the display device left and right and / or up and down.

Therefore, according to the first aspect, the emitted light can be emitted also from the cathode electrode side.

According to the second aspect, a normal image can be projected from one screen, and the back side of the normal image can be projected from the other screen.

According to the third aspect, an image can be displayed even when the lid is closed.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a double-sided organic electroluminescence device according to an embodiment of the present invention;
A display device and an electronic device using the same will be described.

FIG. 1 is a schematic diagram of a double-sided light emitting organic EL device according to a first embodiment of the present invention, FIG. 2 is a schematic diagram of a double-sided light emitting organic EL device of a second embodiment of the present invention, and FIG. FIG. 4 is a conceptual diagram schematically illustrating an electronic device equipped with the dual emission organic EL display device according to the embodiment, and FIG. 4 illustrates a usage pattern of the electronic device with the dual emission organic EL display device illustrated in FIG. 3. FIG. 5 is a diagram showing a dual emission type organic E according to another embodiment of the present invention.
FIG. 6 is an explanatory view showing a usage mode of an electronic device with an L display device, FIG. 6 is an explanatory diagram showing a normal image projected on a dual emission organic EL display device of the electronic device shown in FIG. 3, and FIG. 8 is an explanatory diagram when the normal image shown in FIG. 6 is vertically inverted, and FIG. 8 is an explanatory diagram when the normal image shown in FIG. 6 is horizontally inverted.

The conventional organic EL shown in FIG.
The same components as those of the element 1 are denoted by the same reference numerals, and the description of those components will be omitted.

First, in FIG. 1, reference numeral 1A indicates a double-sided organic EL device according to the first embodiment of the present invention. This double-sided light emitting organic EL element 1A is an element having a structure in which a light guide portion 8 is formed by replacing a part of the cathode electrode 7 with a substance having a high transmittance. Further, like the double-sided light emitting organic EL element 1B of the embodiment shown in FIG.
May be formed to penetrate the electron transport layer 6 and extend to the light emitting layer 5.

Further, in the case of a display device in which the cathode electrodes 7 are formed in parallel (active matrix structure) as shown in FIG. 9, a light guide section 8 may be provided between the cathode electrodes 7. .

As a material of the light guide portion 8, ITO or transparent glass having high transmittance and conductivity is preferably used. If necessary, the surfaces of the cathode electrode 7 and the light guide portion 8 are covered with a transparent glass or the like for sealing and stability during use, thereby forming a transparent protective layer 9.

With the above-described structure, the brightness of the double-sided organic EL device on the cathode electrode 7 side is attenuated as compared with the anode electrode 3 side. Therefore, when the luminance on the cathode electrode 7 side is set to the same level as that on the anode electrode 3 side, the current may be increased by an amount corresponding to the luminance attenuation of the cathode electrode 7.

By configuring the organic EL element in this manner, as shown by the arrows, light is emitted from both sides of the element, and the double-sided organic EL element of the present invention can be obtained.

The above-mentioned double-sided emission type organic EL device 1A, 1B
When the double-sided organic EL device 10 as shown in FIG. 3 is formed by using the above-described method, as shown in FIG. 9, the organic EL device 10 may be formed in an active matrix structure in which the cathode electrodes 7 are formed in parallel. . Then, by applying a signal current to display each of the cathode electrodes 7 having a matrix structure and switching the signals as appropriate, emitted light is emitted from both surfaces thereof, and an image can be displayed.

Next, an electronic device with a double-sided light emitting organic EL display device (hereinafter simply referred to as “electronic device”) will be described with reference to FIGS.

In general, an electronic device such as a notebook personal computer or an electronic organizer is composed of a main body in which a keyboard, a CPU, and various memory devices are built, and a lid on which a display device serving as a lid is attached. When not in use, the main body is closed, and when in use, the lid is opened to project an image on its display surface.

In the electronic apparatus of the present invention, the double-sided light emitting organic EL device 10 of the present invention is incorporated in the cover of the electronic apparatus having the above-described configuration. That is, FIG. 3 shows the electronic device 20A of the present invention. The electronic device 20 includes a main body 21 and the above-described double-sided emission type organic EL device 10 with a lid 22.
Is a device connected to the main body 21 by a hinge (not shown).

The illustrated state is a use state in which the lid 22 is opened. With the lid 22 opened in this manner, a predetermined image is normally projected on the display surface of the double-sided light emitting organic EL device 10, for example, on the side where the anode electrode 3 is formed. . In this case, the opposite cathode electrode 7
The left and right images are projected on the display surface on the side where is formed.

Next, based on the state in which the lid 22 is opened, when the lid 22 is closed as shown in FIG. 4, it is detected that the lid 22 is closed, and the lid 22 is opened. The image projected when the image is displayed is turned upside down and projected on the display surface on the side where the cathode electrode 7 is formed. Lid 2
When 2 is closed to an angle or completely closed, as shown in FIG. 4B, the image is displayed upside down. The image inverting circuit device is built in, for example, the main body 21 side.

The electronic device 20A having such a configuration is provided with a cover 2
2, the user operates the main body 21 to project a desired image, and then, even if the lid 22 is closed, the desired image can be projected as a standing image, for example, in a crowded space such as a commuter train. Inside, the user can view the image.

In the use state shown in FIG. 5, the lid 22 is opened and the back side of the double-sided light emitting organic EL device 10, that is,
In the above example, a desired image is projected from the display surface side on which the cathode electrode 7 is formed. FIG. 5A shows a state in which an image is projected on the display surface of the main body 21 as usual, and FIG. 5B shows a state in which the lid 22 is opened and the state is detected. Is shown on the display surface on the back side of the double-sided light emitting organic EL device 10 with the left and right reversed.

Such an electronic device 20B is used, for example, when a salesman explains a product in a normal image to the customer when the salesman faces the customer and explains the product. It is a suitable device to use.

The image inverting circuit device is a digital video camera "mini DV XX" already sold by the present applicant.
XXXXXXXX DCR-TRV7 ”and the like, and the image projected on the LCD monitor that can be opened and closed with respect to the main body and that can be flipped in the open state is the LCD monitor. When the camera is turned to the subject side in a state in which the camera is open, the image is configured to be displayed upside down, left, right, upside down. Such an image inverting circuit device is a well-known digital video camera equipped with a liquid crystal monitor, which is not only a digital video camera of the present applicant but also almost all digital video cameras with a liquid crystal monitor sold by many other electric and camera manufacturers. Since the technique is a technique, a detailed description thereof will be omitted, but a method of vertically and horizontally inverting an image will be conceptually described below with reference to FIGS. 6 to 8.

First, a normal image projected on the double-sided light emitting organic EL display of the electronic apparatus shown in FIG. 3 will be described with reference to FIG. It is assumed that the screen of the display device has a matrix configuration in which pixels of n rows and m columns are displayed as dots, and n rows and m columns
Let the pixels in the column be a (nm). And hereafter, simply 5
The description will be made as a matrix of × 5. FIG. 6 shows a screen on which a normal image is projected. That is, normal image transfer is performed by a (11), a (12),... A (54), a
(55), starting from one line and ending with five lines.

In the state where the normal image shown in FIG. 6 is displayed, as shown in FIG. 4, in order to close the lid 22 and turn the image upside down, the rows are 1, 2 and .. N, this order is reversed to n, n−1,. The column order is not reversed. As a result, the image is displayed in an array of pixels as shown in FIG.

Further, in a state where the normal image shown in FIG. 6 is projected, as shown in FIG. 5, in order to invert the left and right of the image, columns 1, 2,... In this case, the order is reversed to m, m−1,. Line order is not reversed. As a result, the image is displayed in an array of pixels as shown in FIG.

Double-sided emission type organic E for electronic device 20B
When the L device 10 is attached to the main body 21 so that the display surface on the side viewed by the customer is formed on the display surface on the side where the anode electrode 3 is formed, a clearer image can be displayed. Is easy to see.

However, in the case of the structure of the electronic device 20A and the case of the electronic device 20B, if the luminance on the side where the light guide section 8 is formed is insufficient, the current may be adjusted to an appropriate value. Brightness can be obtained.

[0042]

As described above, according to the dual emission organic EL device and the dual emission organic EL device of the present invention,
The electronic device of the present invention that can display an image from both sides and incorporates the same can display an image even when the lid is closed, or can show the same image to the opponent who is facing, and has excellent effects. can get.

[Brief description of the drawings]

FIG. 1 is a double-sided light emitting organic EL according to a first embodiment of the present invention.
It is a schematic diagram of an element.

FIG. 2 shows a double-sided light emitting organic EL according to a second embodiment of the present invention.
It is a schematic diagram of an element.

FIG. 3 is a conceptual diagram schematically illustrating an electronic apparatus equipped with the dual emission type organic EL display device according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a use form of the electronic device with a double-sided light emitting organic EL display device shown in FIG.

FIG. 5 is a double-sided light emitting organic EL according to another embodiment of the present invention.
It is an explanatory view showing a use form of an electronic device with a display device.

6 is a double-sided light emitting organic EL of the electronic apparatus shown in FIG.
FIG. 4 is an explanatory diagram illustrating a normal image projected on a display device.

FIG. 7 is an explanatory diagram of a case where the normal image shown in FIG. 6 is inverted upside down.

FIG. 8 is an explanatory diagram of a case where the normal image shown in FIG. 6 is horizontally inverted.

FIG. 9 is a conceptual perspective view of a general organic EL element of the related art.

FIG. 10 is a schematic diagram of the organic EL element shown in FIG.

[Explanation of symbols]

1A: Double-sided organic EL device of one embodiment of the present invention,
1B: double-sided light emitting organic EL device of another embodiment of the present invention, 2: glass substrate, 3: anode electrode, 4: hole transport layer, 5: light emitting layer, 6: electron transport layer, 7: cathode electrode,
Reference Signs List 8: light guide, 9: transparent glass, 10: double-sided organic EL device of the present invention, 20A: electronic apparatus of one embodiment of the present invention (with double-sided organic EL device), 20B: other of the present invention Electronic device (with double-sided emission type organic EL device) of the embodiment, 21... Main body of electronic device 20, 22... Lid of electronic device 20

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/22 H05B 33/22 Z F-term (Reference) 3K007 AB00 AB17 BA00 BA06 CA01 CB01 CC00 DA01 DB03 EB00 5C058 AA12 BA20 BA35 5C094 AA01 AA48 AA52 AA56 BA27 CA19 DA08 DA12 DA13 EA04 EA05 EA06 EB02 ED01 FA01 FA02 FA04 FB01

Claims (6)

[Claims] An organic electroluminescent device comprising at least an electron transport layer, an organic light emitting layer, and a hole transport layer laminated between an opaque cathode electrode and a transparent anode electrode, wherein at least the opaque A double-sided light-emitting organic electroluminescent element, wherein a transparent member as a light guide is formed in a part of the cathode electrode. 2. The double-sided light emitting organic electroluminescent device according to claim 1, wherein the transparent member is tin-doped indium oxide (ITO). 3. The organic EL device according to claim 1, wherein the transparent member is a transparent glass. 4. An organic electroluminescence device comprising at least an electron transport layer, an organic light emitting layer, and a hole transport layer laminated between an opaque cathode electrode and a transparent anode electrode, wherein at least the opaque A double-sided organic electroluminescent element, wherein a plurality of double-sided organic electroluminescent elements in which a transparent member as a light guide is formed in a part of a cathode electrode are arranged on a transparent substrate at predetermined intervals. Luminescence display device. 5. A main body in which main components are disposed;
An electronic device comprising: a lid that becomes a lid on the surface of the main body when closed; wherein the lid is at least an electron transport layer and an organic light emitting layer between an opaque cathode electrode and a transparent anode electrode. A plurality of double-sided organic electroluminescent elements in which a hole transport layer is laminated and a transparent member as a light guide part is formed at least in part of the opaque cathode electrode, at predetermined intervals. The main body and / or the lid are formed of a double-sided organic EL display arranged on a transparent substrate. A double-sided organic electroluminescent display device comprising an image inverting means for inverting the organic electroluminescent display device. For example was the electronics. 6. The display device according to claim 5, wherein the inner display surface of the lid is connected to the main body such that the display surface on the side where the light guide portion is not formed. Electronic device with a double-sided organic electroluminescent display device.